MC68307

The MC68307 is an integrated processor combining a static 68EC000 processor with multiple interchip bus interfaces. The MC68307 is designed to provide optimal integration and performance for applications such as digital cordless telephones, portable measuring equipment, and point-of-sale terminals. By providing 3.3 V, static operation in a small package, the MC68307 delivers cost-effective performance to handheld, batterypowered applications.

The MC68307 (shown in Figure 1) contains a static EC000 core processor, multiple bus interfaces, a serial channel, two timers, and common system glue logic. The multiple bus interfaces include: dynamic 68000 bus, 8051 bus, and Motorola bus (M-bus) or I² C bus¹ . The dynamically sized 68000 bus allows 16-bit performance out of static random access memory (SRAM) while still providing a low-cost interface to an 8-bit read-only memory (ROM). The 8051 bus interfaces gluelessly to 8051-type devices and allows the reuse of applicationspecific integrated circuits (ASICs) designed for this industry standard bus. The M-bus is an industry standard 2-wire interface which provides efficient communications with peripherals such as EEPROM, analog/digital (A/ D) converters, and liquid crystal display (LCD) drivers. Thus, the MC68307 interfaces gluelessly to boot ROM, SRAM, 8051 devices, M-bus devices, and memory-mapped peripherals. The MC68307 also incorporates a slave mode which allows the EC000 core to be turned off, providing a 3.3-V static, low-power multi-function peripheral for higher performance M68000 family processors.