Z87C33 Datasheet, PDF (13/72 Pages) Zilog, Inc. – CMOS Z8® MCU Consumer Controller Processor

Z87C33
CMOS Z8“ MCU Consumer Controller Processor
7
Z8
Port 2 (I/O)
Open Drain
Open
PAD
Out
1.5
In
2.3 Hysteresis V_CC @ 5.0V
R _~ 500 kΩ
Auto Latch
(Mask Option)
Figure 4.Port 2 Configuration
Port 3 (P37–P30). Port 3 is an 8-bit, CMOS-compatible port, with four fixed inputs
(P33–P30) and four fixed outputs (P34–P37). Port 3 is configured under software
control for Input/Output, Counter/Timers, interrupt, and UART. Port 3, bit 0 input is
Schmitt-triggered, and pins P31, P32, and P33 are standard CMOS inputs (no
autolatches). Pins P34, P35, P36, P37 are push-pull output lines. Low-EMI output
buffers are globally programmed by the software.
Two onboard comparators process analog signals on P31 and P32 with reference
to the voltage on P33. The analog function is enabled by programming Port 3
PS015601-1003