M80C196KB

PIN DESCRIPTIONS

Symbol

Name and Function

Main supply voltage (5V)

analog portion of the AD converter and the logic used to read Port 0 Must be connected

for AD and Port 0 to function

ANGND

Reference ground for the AD converter Must be held at nominally the same potential as

Timing pin for the return from powerdown circuit Connect this pin with a 1 mF capacitor to

XTAL1

Input of the oscillator inverter and of the internal clock generator

XTAL2

Output of the oscillator inverter

CLKOUT

Output of the internal clock generator The frequency of CLKOUT is

the oscillator

frequency It has a 50% duty cycle

RESET

Reset input to the chip Input low for at least 4 state times to reset the chip The

subsequent low-to-high transition re- synchronizes CLKOUT and commences a 10-state-

time sequence in which the PSW is cleared a byte read from 2018H loads CCR and a

jump to location 2080H is executed Input high for normal operation RESET has an

internal pullup

BUSWIDTH

Input for buswidth selection If CCR bit 1 is a one this pin selects the bus width for the bus

cycle in progress If BUSWIDTH is a 1 a 16-bit bus cycle occurs If BUSWIDTH isa0an

8-bit cycle occurs If CCR bit 1 is a 0 the bus is always an 8-bit bus This pin is the TEST

8