Z8F6421PM020SC Datasheet, PDF (78/299 Pages) Zilog, Inc. – High Performance 8-Bit Microcontrollers Z8 Encore-R 64K Series

Z8 Encore!^® 64K Series
Product Specification
58
AF[7:0]—Port Alternate Function enabled
0 = The port pin is in normal mode and the DDx bit in the Port A–H Data Direction sub-
register determines the direction of the pin.
1 = The alternate function is selected. Port pin operation is controlled by the alternate
function.
Port A-H Output Control Sub-Registers
The Port A-H Output Control sub-register (Table 18) is accessed through the Port A–H
Control register by writing 03H to the Port A–H Address register. Setting the bits in the
Port A–H Output Control sub-registers to 1 configures the specified port pins for open-
drain operation. These sub-registers affect the pins directly and, as a result, alternate func-
tions are also affected.
Table 18. Port A-H Output Control Sub-Registers
BITS
FIELD
RESET
R/W
ADDR
7
POC7
6
POC6
5
POC5
4
POC4
3
POC3
2
POC2
1
POC1
0
POC0
0
R/W
If 03H in Port A-H Address Register, accessible through Port A-H Control Register
POC[7:0]—Port Output Control
These bits function independently of the alternate function bit and disables the drains if set
to 1.
0 = The drains are enabled for any output mode.
1 = The drain of the associated pin is disabled (open-drain mode).
PS019915-1005
General-Purpose I/O