Now that it is finally a free-standing public company, Campbell, California-based Zilog Inc has rediscovered its early creativity, and its latest trick is the Z86C94, claimed to be the first 8-bit microcontroller with a 16-bit signal processor on a single chip. The addition of a signal processor to the company’s Z8 microcontroller enables closed-loop servo functions to be executed digitally, reducing cost and eliminating noise and reliability problems associated with analogue servos. The device also features 8-bit analogue-to-digital and digital-to-analogue converters that are claimed to be extremely fast, a serial peripheral interface and a single channel pulse width modulator. Zilog reckons that the Z86C94 is particularly suited to embedding in 2.5 and 1.8 disk drives, as well as tape drives, speech and data processing equipment, and automotive and consumer electronics. The signal processor operates as a slave processor to the Z8 and is used in applications that require extensive maths calculations. When executed from its own program RAM, it is capable of 16 by 16-bit multiplication and accumulation in one clock cycle, or less than 100nS with a 24MHz system clock. The eight-channel, 8-bit analogue converter is a half-flash converter with a maximum of 1.7 microseconds conversion time. The 8-bit digital to analogue converter has a settling time of three microseconds and a 4-bit digitally controlled gain stage. The single-channel pulse width modulator operates at 40KHz for high-speed motor control. The Z86C93 maths unit is retained on the Z86C94 and enables hardwired 16-bit multiplication and division at lower speeds for less time-critical functions. The Z8 also includes 24 input-output lines, up to 64Kb of addressable external program space, a 256 byte register file and 236 general purpose registers. The part also has three power-down modes for power sensitive applications. Fabricated in 1.2 micron CMOS it’s $15 for 1,000-up, now.
