Z8F640x/Z8F480x/Z8F320x/Z8F240x/Z8F160x
Z8 Encore!®
40
AF[7:0]—Port Alternate Function enabled
0 = The port pin is in normal mode and the DDxbit 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 17) is accessed through the Port A-H
Control register by writing 03Hto 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 17. Port A-H Output Control Sub-Registers
BITS
FIELD
RESET
R/W
7
6
5
4
3
2
1
0
POC7
POC6
POC5
POC4
POC3
POC2
POC1
POC0
0
0
0
0
0
0
0
0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
If 03H in Port A-H Address Register, accessible via Port A-H Control Register
ADDR
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).
PS017610-0404
General-Purpose I/O
ZILOG [ ZILOG, INC. ]
