Z8 Encore! XP
®
4K Series
Product Specification
46
section.
1 = Port Alternate Function selected as defined in Tables 15 and 16 in the
section.
Port A–D Alternate Function Set 2 Sub-Registers
The Port A–D Alternate Function Set 2 sub-register (Table
is accessed through the
Port A–D Control register by writing
08H
to the Port A–D Address register. The Alternate
Function Set 2 sub-registers selects the alternate function available at a port pin. Alternate
Functions selected by setting or clearing bits of this register is defined in
in the
section
Note:
Alternate function selection on port pins must also be enabled as decribed in
.
Table 27. Port A–D Alternate Function Set 2 Sub-Registers (PxAFS2)
BITS
FIELD
RESET
R/W
ADDR
R/W
7
PAFS27
6
PAFS26
R/W
5
PAFS25
R/W
4
PAFS24
R/W
3
PAFS23
R/W
2
PAFS22
R/W
1
PAFS21
R/W
0
PAFS20
R/W
00H (all ports of 20/28 pin devices); 04H (Port A of 8-pin device)
If 08H in Port A–D Address Register, accessible through the Port A–D Control Register
PAFS2[7:0]—Port Alternate Function Set 2
0 = Port Alternate Function selected as defined in
sec-
tion.
1 = Port Alternate Function selected as defined in
sec-
tion.
Port A–C Input Data Registers
Reading from the Port A–C Input Data registers (Table
returns the sampled values
from the corresponding port pins. The Port A–C Input Data registers are read-only. The
value returned for any unused ports is 0. Unused ports include those missing on the 8- and
28-pin packages, as well as those missing on the ADC-enabled 28-pin packages.
Table 28. Port A–C Input Data Registers (PxIN)
BITS
FIELD
RESET
R/W
ADDR
7
6
5
4
3
2
1
0
PIN7
X
R
PIN6
X
R
PIN5
X
R
PIN4
X
R
PIN3
X
R
PIN2
X
R
PIN1
X
R
PIN0
X
R
FD2H, FD6H, FDAH
PS022815-0206
General-Purpose I/O
ZILOG [ ZILOG, INC. ]
