Z08617 Datasheet, PDF (8/26 Pages) Zilog, Inc. – NMOS Z8 8-BIT MCU KEYBOARD CONTROLLER

Port 2 (P27-P20). Port 2 is an 8-bit, bit programmable, bi-
directional, NMOS compatible I/O port. These eight I/O
lines are configured under the software control program
for I/O. Port 2 can be programmed as bit-by-bit indepen-
dently, as input or output, or configured to provide open-
Z08617 NMOS Z8^® 8-BIT MCU
KEYBOARD CONTROLLER
drain outputs (Figure 7). P26 and P27 have 2.4 Kohms
(± 25%) pull-up resistors and are capable of sourcing
2.4 mA. P24 and P25 have 10.4 Kohms (± 35%) pull-up
when configured as inputs.
Z8615
Port 2
(I/O)
OEN
Open-Drain
(a) Ports P20-P23
Pad
OUT
Input
IN
OEN
Open-Drain
(b) Ports P24-P25
OUT
IN
Input
10.4 Kohms
Pad
OEN
Open-Drain
(c) Ports P26-P27
OUT
Input
2.4 Kohms
Pad
IN
Figure 7. Port 2 Configuration
8