Z86L825 Datasheet, PDF (20/79 Pages) Zilog, Inc. – 20-Pin Low-Voltage IR Microcontrollers

Z86L825/826/827
20-Pin Low-Voltage IR Microcontrollers
13
Pin Functions
XTAL1 Crystal 1 (Time-Based Input)
This pin connects a parallel-resonant crystal, ceramic resonator, LC, or RC net-
work or an external single-phase clock to the on-chip oscillator input.
XTAL2 Crystal 2 (Time-Based Output)
This pin connects a parallel-resonant crystal, ceramic resonant, LC, or RC net-
work to the on-chip oscillator output.
Port 0 (P00,01,07)
Port 0 is a 3-bit, bidirectional, CMOS-compatible port. These three I/O lines are
configured under software control as a nibble I/O port. The output drivers are
push-pull or open drain controlled by bit D2 in the PCON register.
If one or both nibbles are required for I/O operation, they must be configured by
writing to the Port 0 mode register. After a hardware reset, Port 0 is configured as
an input port.
A mask option is available to program 0.4 V_DD CMOS trip inputs on P00–P01.
This allows direct interface to mouse/trackball IR sensors.
Port 0 has a 200 ±50%KΩs pull-up transistor built in. See Figure 6.
Note: Internal pull-ups are disabled on any given pin or group of port
pins when programmed into output mode.
PS008808-1203
PRELIMINARY