SM470R1B1M-HT

The SM470R1B1M⁽³⁾ devices are members of the Texas Instruments SM470R1x family of general-purpose 16-/32-bit reduced instruction set computer (RISC) microcontrollers. The B1M microcontroller offers high performance using the high-speed ARM7TDMI 16-/32-bit RISC central processing unit (CPU), resulting in a high instruction throughput while maintaining greater code efficiency. The ARM7TDMI 16-/32-bit RISC CPU views memory as a linear collection of bytes numbered upwards from zero. The SM470R1B1M uses the big-endian format where the most significant byte of a word is stored at the lowest numbered byte and the least significant byte of a word is stored at the highest numbered byte.

High-end embedded control applications demand more performance from their controllers while maintaining low costs. The B1M RISC core architecture offers solutions to these performance and cost demands while maintaining low power consumption.

The B1M devices contain the following:

• ARM7TDMI 16-/32-bit RISC CPU
• SM470R1x system module (SYS) with 470+ enhancements
• 1MB flash
• 64KB SRAM
• ZPLL clock module
• DWD timer
• AWD timer
• Enhanced RTI module
• IEM
• MSM
• JTAG security module
• Two SPI modules
• Three SCI modules
• Two HECC
• Five I²C modules
• 10-bit MibADC, with 12 input channels
• HET controlling 12 I/Os
• ECP
• EBM
• Up to 93 I/O pins

The functions performed by the 470+ system module (SYS) include:

• Address decoding
• Memory protection
• Memory and peripherals bus supervision
• Reset and abort exception management
• Prioritization for all internal interrupt sources
• Device clock control
• Parallel signature analysis (PSA)

The enhanced RTI module on the B1M has the option to be driven by the oscillator clock. The DWD is a 25-bit resettable decrementing counter that provides a system reset when the watchdog counter expires. This data sheet includes device-specific information such as memory and peripheral select assignment, interrupt priority, and a device memory map. For a more detailed functional description of the SYS module, see the TMS470R1x System Module Reference Guide (SPNU189).

The B1M memory includes general-purpose SRAM supporting single-cycle read/write accesses in byte, half-word, and word modes.

The flash memory on this device is a nonvolatile, electrically erasable, and programmable memory implemented with a 32-bit-wide data bus interface. The flash operates with a system clock frequency of up to 24 MHz or 30 MHz, depending on the input voltage. When in pipeline mode, the flash operates with a system clock frequency of up to 48 MHz or 60 MHz, depending on the input voltage. For more detailed information on the flash, see 8.2.1.4.

The MSM and the JTAG security module prevent unauthorized access and visibility to on-chip memory, thereby preventing reverse engineering or manipulation of proprietary code.

The B1M device has twelve communication interfaces: two SPIs, three SCIs, two HECCs, and five I²Cs. The SPI provides a convenient method of serial interaction for high-speed communications between similar shift-register type devices. The SCI is a full-duplex, serial I/O interface intended for asynchronous communication between the CPU and other peripherals using the standard non-return-to-zero (NRZ) format. The HECC uses a serial, multimaster communication protocol that efficiently supports distributed realtime control with robust communication rates of up to 1 Mbps. These CAN peripherals are ideal for applications operating in noisy and harsh environments (for example, industrial fields) that require reliable serial communication or multiplexed wiring. The I²C module is a multimaster communication module providing an interface between the B1M microcontroller and an I²C-compatible device through the I²C serial bus. The I²C supports both 100 Kbps and 400 Kbps speeds. For more detailed functional information on the SPI, SCI, and CAN peripherals, see the specific reference guides (SPNU195, SPNU196, and SPNU197). For more detailed functional information on the I²C, see the TMS470R1x Inter- Integrated Circuit (I2C) Reference Guide (SPNU223).

The HET is an advanced intelligent timer that provides sophisticated timing functions for realtime applications. The timer is software-controlled, using a reduced instruction set, with a specialized timer micromachine and an attached I/O port. The HET can be used for compare, capture, or general-purpose I/O. It is especially well-suited for applications requiring multiple sensor information and drive actuators with complex and accurate time pulses. The HET used in this device is the high-end timer lite. It has fewer I/Os than the usual 32 in a standard HET. For more detailed functional information on the HET, see the TMS470R1x High-End Timer (HET) Reference Guide (SPNU199).

The B1M HET peripheral contains the XOR-share feature. This feature allows two adjacent HET high-resolution channels to be XORed together, making it possible to output smaller pulses than a standard HET. For more detailed information on the HET XOR-share feature, see the TMS470R1x High-End Timer (HET) Reference Guide (SPNU199).

The B1M device has one 10-bit-resolution, sample-and-hold MibADC. Each of the MibADC channels can be converted individually or can be grouped by software for sequential conversion sequences. There are three separate groupings, two of which can be triggered by an external event. Each sequence can be converted once when triggered or configured for continuous conversion mode. For more detailed functional information on the MibADC, see the TMS470R1x Multi-Buffered Analog-to-Digital Converter (MibADC) Reference Guide (SPNU206).

The ZPLL clock module contains a phase-locked loop, a clock-monitor circuit, a clock-enable circuit, and a prescaler (with prescale values of 1 to 8). The function of the ZPLL is to multiply the external frequency reference to a higher frequency for internal use. The ZPLL provides ACLK to the system (SYS) module. The SYS module subsequently provides system clock (SYSCLK), realtime interrupt clock (RTICLK), CPU clock (MCLK), and peripheral interface clock (ICLK) to all other B1M device modules. For more detailed functional information on the ZPLL, see the TMS470R1x Zero-Pin Phase-Locked Loop (ZPLL) Clock Module Reference Guide (SPNU212).

ACLK should not be confused with the MibADC internal clock, ADCLK. ACLK is the continuous system clock from an external resonator/crystal reference.

The EBM is a standalone module that supports the multiplexing of the GIO functions and the expansion bus interface. For more information on the EBM, see the TMS470R1x Expansion Bus Module (EBM) Reference Guide (SPNU222).

The B1M device also has an external clock prescaler (ECP) module that when enabled, outputs a continuous external clock (ECLK) on a specified GIO pin. The ECLK frequency is a user-programmable ratio of the peripheral interface clock (ICLK) frequency. For more detailed functional information on the ECP, see the TMS470R1x External Clock Prescaler (ECP) Reference Guide (SPNU202).