MCU User Guide based on ARM
Preface
As the most popular processor which grasps the highest market share in the world, ARM boasts abundant technical documents on the Internet or in libraries. So this article will not introduce the abstruse architecture and the complicated software programming in detail, but show you how to select a MCU suitable for your design and describe most of required devices that constitute the whole system.
The market situation of ARM processor
MCUs, as the core devices in electronic products, can be found in almost all the products from the area of aeronautics, astronautics, automobile, medical care to consumer electronics. Currently, about 40 billion units of embedded chips were delivered every year in the global market, most of which are still 4-bit and 8-bit CPUs. However, the remarkable rising of 32-bit processor has made it the most brilliant star. In 2007, WSTS reported that the 32-bit MCU market has increased by 100% approximately over the last 5 years, the gross sales in 2007 increased by 13.6% comparing with that in 2006, which account for 30.8% of the global market share. The report said that 32-bit MCU has successfully surpassed 16-bit MCU, and anticipated that it will beat 8-bit MCU in 2009. This trend is driving manufacturers step by step into the competition field of 32-bit.
ARM, the former Acorn Computer Company, was formally established in 1990. ARM is not a company profiting from designing and manufacturing chips, but selling its IP (Intelligence Property) products including hard-core and soft-core to the major semiconductor manufacturers. Because of many remarkable advantages such as small size, low power consumption, low cost and high performance/price ratio, ARM core obtained full support from many manufacturers. After being licensed by ARM, manufacturers would design an ARM processor typically by 2 methods: one is using ARM core to design a ASIC processor or SoC (Majority of Cell phone, DVD Player, STB, MP3 belong are based on SoC), another is using ARM core to design a general-purpose processor, which will be the very focus of this article – 32-bit MCU based on ARM.
The information from the ARM website shows that more than 200 semiconductor manufacturers from all around the world has become the licensed clients of ARM, including the leading manufacturers of MCU such as Freescale, TI, NXP, ST, Atmel, Intel, Altera, Samsung, Renesas, etc., and also the major manufacturers of ASIC SoC for communication - Qaulcomm and Broadcom.
ARM Architecture and Design Support
ARM Architecture
ARM core employs RISC architecture that is widely used by embedded processors, reasonably improving the performance of MCU through fixed instruction length, fewer instruction formats and addressing modes, mainly basing on control logic, less use or non-use of microcode control. Some of the features of RISC and ARM architectures are shown below:
- Employing uniform, fixed-length and simple instruction fields, 2 to 3 basic addressing modes.
- Employing single cycle instructions, suitable for pipelining execution.
- Using lots of registers, data processing instructions only operates on registers, while memories can only be accessed by load/store instructions, optimizing the execution efficiency of instructions.
- Improving the execution efficiency of instructions by executing instructions based on the result generated by the previous one.
- Improving the data transfer efficiency by transferring data in bathes through load/store instructions.
- Logic and shift processing can be done by one data processing instruction.
- Optimizing program loops by auto-increment and auto-decrement addressing modes.
ARM core supports 32-bit ARM instruction set and 16-bit high code density Thumb subset. Comparing between the ARM and Thumb codes for the same functionality, the latter can save over 30%-40% of storage space, while has all the merits of 32-bit codes.
ARM OS support：
Owing to the wide range of ARM MCU applications and numerous chip manufacturers, there are a lot of alternatives for the RTOS (Real Time Operating System) of ARM MCU. The well known RTOS includes: Linux, Symbian, VxWorks, Nucleus, Windows CE and μCOS, etc. Something should be noticed is that Linux and Windows CE operating systems need MMU support, and are not suited to be used on ARM7TDMI core.
ARM development tools：
ARM development tools are dedicated for developing ARM processor-based MCU, its integrated development environment can provide developers with all the functions needed from the beginning to the ending stage of product development, ensuring the perfect performance of ARM IP core. ARM development tools include the early ADS, as well as RealView Development Suite 4.0 Professional and RealView Development Suite 4.0 Standard, which are vigorously promoted by ARM.
The platform provided by RealView development tools allows hardware engineers easily design the ASIC prototype and peripherals, and can seamlessly bridge the gap between the software and hardware worlds. It also helps software engineers faster deliver better products from applications running on open operating systems right through to low-level firmware. Architects and developers can create and validate their hardware design ideas under the assistance of configurable hardware platforms and virtual prototypes in RealView development tools. RealView development tools, as the first choice for embedded processor development, give you confidence in your final product much earlier in the design cycle, therefore lowering risk and increasing design quality
How to Select an ARM MCU in Our Design?
ARM Processor Family：
The first matter should be considered before a designer starts to design an embedded product is what MCU is required. The MCU may not be the fastest one, or the one with best performance or with lowest price, but it must be the most suitable MCU with the best performance/price ratio. The ARM processor families include ARM7, ARM9, ARM9E, ARM11, Cortex and SecurCore. Designers can find the family that meets their requirements based on the following descriptions of ARM processors. ARM7 Family: ARM7TDMI is the most widely used core of ARM7 Family. It is based on ARM v4, employing Von Neumann architecture, with 3-stage pipelining, 0.9 DMIPs/Mhz average performance. Other members of ARM7 family include ARM720T and ARM7E-S. ARM9 Family: In comparison with ARM7TDMI, ARM9TDMI increased the pipelining up to 5 stages, resulting in the increment of processor frequency. It takes advantage of Harvard architecture which has individual memories for the storage of instruction and data, improving CPI and processor performance at 1.1DMIPs/Mhz in average. In addition to ARM9TDMI, there are also ARM920T, ARM940T and ARM922T which better support the multi-thread, multi-task operating system like Linux and WinCE. ARM9E Family: ARM9E family is synthesizable core which is based on ARM v5TE, integrated with more extended instructions than ARM9TDMI; the members include RM968E-S, ARM966E-S, ARM946E-S and ARM926EJ-S, among them ARM926EJ-S is the major representative. Taking advantage of the DSP and Java extended instructions, the DSP performance can be increased by 70% and Java processing can be enhanced by 8 times. ARM11 Family: The members of ARM11 family mainly include ARM1136, ARM1156, ARM1176 and ARM11 MP-Core. ARM11 family is designed to meet the requirements of next generation consumer electronics, wireless devices, network applications and automotive electronics. ARM Cortex Family: Cortex family is the newest series core of ARM at present. It is based on v7 architecture, and the main members have Cortex-A8, Cortex-R4, Cortex-M3 and Cortex-M1. A8 is a high performance application processor with speed up to 1 GHz and processing capacity of 2000DMIPS, better satisfying the requirements of multimedia and other applications for high performance; R4 is mainly used for embedded real-time applications, with 7-stage pipelining, processing speed of over 400 MHz and processing capacity of over 1.5DMIPS/Mhz, it gives better balance in PPA (Performance, Power and Area). M3 is mainly applied in low cost and high performance applications. The ARM® SecurCore® processor family provides powerful 32-bit solutions for smart card and secure IC development, offering system designers access to ARM processors to create fast, secure solutions for SIM, pay TV, banking, networking, mobile multimedia, identification and mass transit applications. In addition to very small die size, low power consumption, code density and performance, the SecurCore family incorporates special security features to help defend against many advanced forms of attack. The SC100 and SC200 are the two members of the family.
ARM MCU selection guide based on peripheral interface：
There are numbers of semiconductor manufacturers designing ARM MCU, different manufacturers design the MCU with different peripherals based on their own market positioning (see Appendix). So, there is another important method to select MCU - picking out the required MCU based on the capacity of on-chip flash and SRAM, as well as peripherals configuration on the different MCU. The following sections will introduce the method in detail. The MCU used in automotive electronics should have small size, low power consumption, CAN and LIN bus as well. NXP LPC2917/9 MCU has 2 CAN and 2 LIN buses, the current consumed by the core working at 1.8 V is only 1.1mA/MHz under normal condition, with 768KB on-chip flash and 80KB on-chip RAM, making it ideal for engine and other automotive electronics. In addition, TI TMS470/M series MCUs are also designed specially for automotive electronics. The MCU used in audio and video products should better include the peripherals such as LCD controller, CCIR, IIS, etc. in order to simplify design and cut down cost. Meanwhile, the audio and video processing needs modules like dedicated graphics accelerating engine and a great deal of memories, the selected MCU should better support EMI (External Memory Interface）to connect external flash or DDR memory. The iMX27 and iMX31 series from Freescale are the best choices for this kind of application, for example, the design of IP camera. The Xscale from Intel is also widely used in PDA and other products. In many industrial applications, MCU is playing an important role of accurate speed controlling and signal detection of current and load in motors. Selecting an ARM MCU which has multiple PWM controllers and multi-channel high precision ADC can improve system performance and simplify design. ADUC7xxx series MCUs from ADI have a 16-channel 12-bit ADC with resolution up to 1MSPS, and three-phase PWM controller, making them suitable for motor control; the STM32 series MCUs from ST have an 8-channel PWM controller and a 16-channel 10-bit ADC, which is suitable for motor control. Complicated application environment requires the MCUs integrated with more IO and other resources such as I2C and SPI. If I2C bus is needed to control RF or IF devices and typical digital circuit, the dedicated I2C bus would be better. Therefore, a MCU with multiple I2C control bus is required, for example, the LPC24xx series from NXP and the Ep93xx series from Cirrus Logic. The applications that need extension of flash or DDR capacity require the MCUs integrated with EMI (External Memory Interface) and DDR controller. There are wide range of selections for this kind of MCU, such as i.MX series from Freescale; LH7xxx, LPC29xx and LPC24xx series from NXP, EP73xx and EP93xx series from Cirrus Logic, AT91SAM7xxxx series from Atmel, etc. The environment that needs USB function requires the MCUs integrated with USB host or USB OTG. Currently most of MCUs are integrated with USB function, which makes selection easier. The LPC24xx and LPC2917/19 from NXP has the inbuilt USB 2.0 host, the controller of device and OTC as well as physical layer, decreasing the design workload of external circuit. It is obviously better to select the MCU integrated with ADC or DAC for the applications that need ADC or DAC function. The ADUC7xxx series MCUs from ADI have a 16-channel 12-bit ADC and a 4-channel DAC, which is the MCU that incorporates the most abundant ADC and DAC resources. The MCU integrated with Ethernet MAC module or PCI controller should be taken into consideration when designing a system with Ethernet function. For example, the EP93xx series from Cirrus Logic and the LPC24xx series from NXP can provide Industrial Standard Media Independent Interface (MII). With the prevailing trend to system-on-chip (SoC) in the semiconductor industry, many manufacturers have introduced their Hybrid ARM/DSP chips. The DaVinci™ TMS320DM64xx and TMS320DM3xx series from TI is integrated with the C64x DSP and ARM926EJ-S core, becoming the ideal choice for digital multimedia products; OMAP35x series is integrated with C64x DSP core and ARM Cortex™-A8 processor, which has been widely used in many fields including portable medical devices; the AT91CAP9xxx series from Atmel is integrated with ARM926EJ-S and MP Block, which is also a good choice. Selecting an appropriate MCU is just one of the steps of embedded system design; designers need to put more efforts into the selection of peripherals to build a complete solution. The following sections will introduce how to select peripherals for MCU, including power, voltage supervisor, Operational Amplifier, etc.
How to Select Analog and Power Devices for MCU System Design?
Power Module：
As an indispensable part of any electronic product, power device deserves its important position in design. Because the MCU features low power consumption, the selection of power devices appears simply in a wide range. Typically, the output current range from 300 mA to 3 A can meet the requirements for power supply of the system as long as the output voltage level is satisfying. Accurate selection of power supply has to be determined by the actual MCU part number and the complexity of the system. Based on the considerations that the different core voltages are required by the MCUs using different process, and some of MCUs has inbuilt LDO or DC-DC devices to provide core voltage, it is nearly impossible to clearly illustrate all the possible conditions in only one block diagram, but the following block diagram can basically show us the typical conditions needed by our topic. Certainly, a simple MCU can be satisfied by only a single 3.3 V input voltage. If the cost and simplicity of design are the matters of consequence, a linear voltage regulator is apparently a good choice. All of the linear voltage regulators only need a few of resistors and capacitors to meet the system requirements. LM1117 or LM1085 is the most often used regulator in power supply, and many manufacturers including National, TI, ON Semi are providing this kind of product. The table shown below is a summary of the newest products from the major power chip suppliers around the world at present. Mfr Part Number Vin(V) Vo(V) Io(A) EN Farnell Code Nework P/N National LP38690/2 2.7-10 1.8/2.5/3.3/5 1 Y National LP38691/3 2.7-10 1.8/2.5/3.3/5 0.5 Y National LP38841 6 0.8/1.2/1.5 0.8 Y National LP3871/4 7 1.8/2.5/3.3/5 0.8 Y TI TPS79501/25/xx 2.7-5.5 1.2-5.5 0.5 Y TI TPS77501/18/xx 2.7-10 1.5-5.5 0.5 Y TI TPS77701/33/xx 2.7-10 1.5-5.5 0.7 Y TI TPS72501/15/xx 1.8-6 1.5-5.5 1 Y TI TPS79601/25/xx 2.7-5.5 1.2-5.5 1 Y LTC LTC3026 1.14-5.5 0.4-2.6 1.5 Y LTC LTC3025EDC-2#PBF 0.9-5.5 0.4-3.6 0.5 Y LTC LTC3025EDC-2#PBF 1.7-5.5 0.4-3.6 0.3 Y LTC LTC3021 0.9-10 1.2/1.5/1.8 0.5 Y LTC LT1587 2.7-7 1.5/3.3/3.6 3 N Maxim MAX1793EVE15 2.5-5.5 1.25-5 1 Y Maxim MAX1857 2.5-5.5 1.25-5 0.5 Y Maxim MAX1792 2.5-5.5 1.25-5 0.5 Y Maxim MAX1806 2.5-5.5 0.8-4.5 0.5 Y Maxim MAX603/4 2.7-11 1.25-11 0.5 Y Fairchild FAN1112DX 18 1.2 1 N Fairchild FAN1117ADX 18 1.8/2.5/3.3/5 1 N Fairchild FAN1540 4.5-7 3.3 1.3 Fairchild FAN1589 7 1.2 2.7 ON MC33269 20 3.3/5 0.8 N ON MC33275 13 2.5/3/3.3/5 0.3 N ON MC33375 12 1.8/2.5/3/3.3/5 0.3 N ON NCP5500/1 18 1.25-5 0.5 Y Table 1 - Linear Voltage Regulator Table In the case that the power consumption of a system is specifically restricted, selection of voltage regulator which is inefficient leads to more power consumption. In stead DC/DC step down power chips with high efficiency should be taken into consideration for system design. As always, we will select some of the power chips that can meet those requirements for your reference, as shown in the following table. Mfr Part Number Vin(V) Vo(V) Io(A) Farnell Code Nework P/N National LM3671 2.7-5.5 1.1-3.3 0.6 National LM3674MF-ADJ/NOPB 2.7-5.5 1.1-3.3 0.6 National LM2830XMF/NOPB 3-5 0.6-4.5 1 National LM2574 4-40 Adjustable 0.5 National LM2831 3-5.5 0.6-4.5 1.5 TI TPS62260/1/2/3 2-6 0.6-6 0.6 TI TPS62200/1/2/3/4 2.5-6 0.7-6 0.3 TI TPS62220/1/2/3/4 2.5-6 0.7-6 0.4 TI TPS62300/1/2/3/5 2.5-6 0.6-5.4 0.5 TI TPS63000/1/2 1.8-5.5 1.2-5.5 1.2 ON LM2596 40 1.23-37 3 ON MC33063 3-40 Adjustable 1.5 ON NCP3063 40 Adjustable 1.5 ON NCP34063 3-40 Adjustable 1.5 ON NCP1521BSNT1G 2.7-5.5 0.9-3.9 0.6 Table 2 - DC/DC Step down Table More importance should be attached to the power supply in the design of portable devices; In addition to the power supply satisfying the requirements of system, it is necessary to consider the battery charge and power management in order to ensure longer battery life. Not only should the more efficient DC/DC step up (see table 3) or DC/DC step down chips be taken into consideration, but also a powerful power management chip is absolutely necessary. The table shown below brings you some of the power management chips often used for battery power supply. Mfr Part Number Topology Vin(V) Vo(V) Io(A) Farnell Code Nework P/N TI TPS61100/3/6/7 Boost 0.8-3.3 1.5-5.5 0.8 TI TPS61020/4/5/7 Boost 0.9-5.5 1.8-5.5 0.5 TI TPS61026/9 Boost 0.9-5.5 1.8-5.5 0.6 TI TPS61090/1/2 Boost 0.9-5.5 1.8-5.5 0.7 TI TPS61030/1/2 Boost 1.8-5.5 1.8-5.5 1 ON NCP1450ASN50T1G. - 0.9 1.9-5 1 LTC LT1316CMS8#PBF Boost 1.5-12 5 0.5 LTC LT1173 Boost 2-12 12.9 1 LTC LT1301 Boost 1.8-10 20 0.75 LTC LT3427 Boost 1.8-5 5.25 0.5 LTC LTC3525ESC6-3#PBF Boost 0.85-4.5 5 0.4 Table 3 - DC/DC Step up Table Mfr Part Number Topology Cell# Vimx Iomx Farnell Code Nework P/N TI BQ24120/3/5 Switch 1/2/3 20V 2A TI BQ24010/2/3/4/8 Linear 1 18V 1A TI BQ24400/1 Switch Multi 7V >2A TI BQ24025 Linear Multi 7V 1 TI BQ2000/2/3 Switch Multi 7V >2A National LM3420 1/2/3/4 20V National LM3658 1 6V 1A National LP3947 1 6V 0.75A LTC LTC1510/1/2/3 12 7.8V 1.5A LTC LTC1960 LTC LTC3576 LTC LTC4001 LTC LTC4052 Maxim DS2438AZ+ Maxim DS2711 Maxim DS2762 Maxim DS2780 Maxim MAX1501 ADI ADP2291ARMZ-R7 1 12V 1.5A Intersil ISL6291/2/3 1 7V 2A Intersil ISL88731 1-4 Intersil ISL9205/6 1 7v 1A Intersil ISL9301 1 28 0.8A Micrel MIC79050 1 ON NCP1800 1 16V ON NCP1835 1 16V ON MC33340/2 Table 4 - Battery Charge Table Most of designs that are based on MCU will not use EMI (External Memory Interface), but for the design using the MCUs like the iMX27, iMX31 series from Freescale for multimedia applications (for example, IP camera), the external DDR or DDR2 memory can not be ignored. Therefore, both the power supply and DDR termination regulator need to be considered. Some of DDR termination regulators are listed below. Mfr Part Number DDR DDR2 DDR3 Farnell Code Nework P/N National LM2995M Y - - National LM2996M Y - - National LM2997M - Y - National LM2998M Y Y - TI TPS51200DRCT. Y Y Y TI TPS51100 Y Y Y TI TPS40042 Y Y Y TI TPS54372 Y Y Y ON NCP5208 Y Y - - LTC LTC3831 Y - - LTC LTC3413 Y - - LTC LTC3717 Y - - LTC LTC3718 Y - - Table 5 - DDR Termination Regulator Table It is better to use a dedicated power reset circuit to offer the stable reset and operation environment for MCU. Doing this can ensure accurate reset and correct execution of codes when MCU is powered on or working under an abnormal power supply, and help prevent code runaway that threatens system safety (A collection of power reset chips can be found in the following table). Moreover, some of the complicated MCUs need a strict power-on process to ensure the various modules in the chips are powered in a right sequence (see Table 1). Thus the system power chips have to be integrated with output enable function to control the power-on sequence. Mfr Part Number VTH Vin(V) /MR Active Farnell Code Nework P/N Maxim MAX811 2.5-5.5 Y L Maxim MAX6854 1.2-5.5 Y L - Maxim MAX6326 1.8-3.3 N L TI TPS3808 1.7-3.3 1.8-6.5 Y L TI TPS3125 1.2/1.5/1.8/3 0.75-3.3 Y L/H TI TPS3823 2.5/3/3.3/5 1.1-5.5 Y L TI TPS3824 2.5/3/3.3/5 1.1-5.5 - L/H TI TPS3836 1.8/2.5/3/3.3 1.6-6 Y L MicroChip MCP120/1 2.62/3.075/4.47 1-5.5 N L MicroChip MCP1316/7/8 2.83/4.49 1-5.5 Y L/H MicroChip MC809 2.55/3/4.6 1-5.5 N L MicroChip TC1232 4.5/4.25 4.5-5.5 Y L/H ON NCP300/1 0.9/1.8/2.2/4.7 12 N L/H ON NCP302/3 0.9/1.8/2.2/4.7 0.8-10 N L/H - ON NCP305 0.9/1.8/2.2/4.7 0.8-10 N L/H Table 6 Power Reset Chips Table
Parts LP38690DT-3.3 LP38691SD-ADJ LP38841MR-ADJ LP3871EMP-3.3/NOPB TPS79501DCQG4 TPS77501D TPS77733PWP . TPS72501DCQR. TPS79601DCQG4 LTC3026EDD#PBF LTC3025EDC-2#TRMPBF LTC3035EDDB#PBF LT3021EDH#PBF LT1587CM#PBF MAX1793EUE33+ MAX1857EUA47+ MAX1792EUA15+ MAX1806EUA33+ MAX603ESA+ FAN1112DX FAN1117ASX FAN1540BMPX FAN1589DX MC33269D-3.3G MC33275DT-3.3G MC33375ST-1.8T3G NCP5501DT15G
High precision Amplifier
The noise generated by digital circuit is fatal to the high precision operational amplifier which requires high quality of input signals, so it is hard to integrate it into back-end chips. This kind of amplifiers is widely used as the pre-amplifiers or buffers in the areas such as automobile, medical care, industrial control, test and measurement, etc. The following table shows the high precision amplifiers widely used in the industries. Mfr Part Number No. of Ch Power Supply(V) Vos (uV) CMRR (db) Drift (uV/C°) Rail-Rail Farnell Code Nework P/N National LMP2021/2 1/2 2.2-5.5 5 139 20 O National LMP7731/2 1/2 1.8-5.5 40 130 1 I National LMP7707/8/9 1/2/4 2.7-12 200 130 1 I/O National LMP7717/8 1/2 1.8-5.5 150 100 1 O Maxim MAX4238/9 1 2.7-5.5 2 140 10 O Maxim MAX4236/7 1 2.4-5.5 50 102 5.5 O Maxim MAX4208/9 1 2.85-5.5 20 135 0.2 O Microchip MCP6031/2/3/4 1/2/1/4 1.8-5.5 150 70 3 I/O Microchip TC7652 1 6.5-16 5 120 0.01 O - Microchip MCP6V01/2/3 1/2/1 1.8-5.5 2 130 0.05 I/O Microchip MCP6V06/7/8 1/2/1 1.8-5.5 3 120 0.05 I/O Microchip TC913A/B 2 6.5-16 15 110 0.15 - TI TLC2652/A/Y 1 3.8-16 1 120 0.003 - TI OPA2734/5 2 1.35-6 5 115 10 O TI OPA734/5 1 1.35-6 5 115 10 O TI OPA334/5 1 2.7-5.5 5 110 0.02 O TI OPA2334/5 2 2.7-5.5 5 110 0.02 O TI OPA211 1 4.5-36 50 114 O Cirrus Logic CS3003/4 1/2 2.7-6.7 10 120 0.05 I/O Cirrus Logic CS3013/4 1/2 2.7-6.7 10 120 0.05 O Cirrus Logic CS3001/2 1/2 2.7-6.7 10 120 0.05 O Cirrus Logic CS3011/12 1/2 2.7-6.7 10 120 0.05 O LTC LTC1050/1/2/3 1/2/1/4 4.75-16 5 120 0.5 O LTC LTC6081/2 2/4 2.7-5.5 70 100 0.8 I/O LTC LTC2050/1/2/HV 1/2/4 2.7-5.5 3 130 0.03 O LTC LTC6078/9 2/4 2.5-5.5 25 95 0.7 I/O LTC LTC1152 1 2.7-14 10 115 0.1 I/O ADI AD8638/9 1/2 5-16 9 118 60 O ADI OP1/2/4/177 1/2/4 ±2.5-±15 15 120 0.7 - ADI OP97 1 ±2.5-±20 20 114 0.6 - ADI AD8551/2/4 1/2/4 2.7-5 1 130 0.005 I/O ADI AD8605/6/8 1/2/4 2.7-5.5 65 100 4.5 I/O Table 7 - High precision Amplifier Table #Appendix: MCU Based on ARM Part List Supplier Part Number Core Speed(Mhz) DMA Ch Memory Cache E-Memory ADC Ch DAC Ch Timer Interface I/Os Video Interface LCD Controller Flash(KB) RAM(KB) I (KB) D(KB) Flash SDRAM DDR 10bit 12bit 10bit 12bit PWM WDG/RTC SPI IIC Urat USB IrDA IIS CAN LIN Ethernet Cirrus Logic EP73xx ARM®720T 90 48 8 √ 1 1 1 1 1 √ EP93xx ARM920T 200 12 16 16 √ 2 √ 1 6 3 3* Host 1 √ √ TI TMS470R1B1MPGEA. ARM7TDMI® 16 1000 64 5 2 97 TMS470M Cortex® M3 ADI ADUC7xxx ARM7TDMI® 62 8 √ 16 4 3 √ 2 √ 40 ST STM32 Cortex® M3 64 8 21 8 √ √ √ √ √ √ √ 112 STR7 ARM7TDMI® 32 8 16 √ √ √ √ √ √ √ √ 112 STR9 ARM966E-S 256 12 8 √ √ √ √ √ √ √ √ √ 80 Free scale MAC7xxx ARM7TDMI-S™ 48 √ 16 √ √ 128 i.MXS ARM920TTM 100 11 16 16 √ √ √ 1 1 2 Device 1 1 √ i.MXL ARM920T 200 11 16 16 √ √ √ 1 1 2 Device 1 1 √ √ i.MX21S ARM926EJ-STM 350 16 6 16 16 √ √ √ 2 1 3 1.1O/D 1 1 √ i.MX21 ARM926EJ-S 350 16 6 16 16 √ √ √ √ 2 1 4 1.1OTG/D 1 1 √ √ i.MX27L ARM926EJ-S 400 16 45 16 16 √ √ √ √ 2 1 6 2.0O/H 1 1 √ √ i.MX27 ARM926EJ-S 400 16 45 16 16 √ √ √ √ 2 1 6 2.0O/H 1 1 √ √ i.MX31L ARM1136JF-STM 532 32 16 16 16 √ √ √ √ 2 1 5 2.0O/H 1 1 √ √ i.MX31 ARM1136JF-S 532 32 16 16 16 √ √ √ √ 2 1 5 2.0O/H 1 1 √ √ NXP LPC3180FEL320,551 ARM926EJ 208 2 64 32 32 √ √ 2 2 2 7 2.0O/D/H 55 LPC24xx ARM7TDMI-S 72 √ 512 98 √ 8 1 6 1 3 3 4 2.0O/D/H 1 2 √ √ 160 LPC2880/88 ARM7TDMI 60 √ 1000 64 √ 5 √ 1.1/2.0D 2 √ LPC2917/19 ARM968E-S 768 80 16 16 16 6 √ 3 2 2 2 √ 108 LH7A400/4N ARM922T 250 10 8 8 √ √ 1 1 3 2.0 D 1 60 √ Atmel AT91SAM7xxxx ARM7TDMI® 19 512 128 √ 8 4 1 2 3 FS 1 88 √ Luminary Micro LM3S100 Cortex™-M3 20 8 2 √ √ √ √ 18 LM3S600-IQN50-C2 Cortex™-M3 50 32 8 8 6 √ 1 1 2 36 LM3S800-IQN50-C2 Cortex™-M3 50 64 8 8 6 √ 1 1 2 60 LM3S1000 Cortex™-M3 50 256 64 8 6 √ 2 2 3 60 LM3S2000 Cortex™-M3 50 256 64 8 6 √ 2 2 3 2 60 LM3S6000 Cortex™-M3 50 256 64 8 6 √ 2 2 3 √ 60 LM3S8000 Cortex™-M3 50 256 64 8 6 √ 2 2 3 3 √ 46 TI TMS320DM646x ARM926EJ-S + C64x DSP TMS320DM644x ARM926EJ-S + C64x DSP TMS320DM3xx ARM926EJ-S + MPEG4/JPEG Co processor OMAP35x Cortex™-A8 + C64x DSP