w65c21 Western Design Center, Inc., w65c21 Datasheet - Page 11

• Manufacturer Part Number: w65c21
• Description: W65c21n And W65c21s Peripheral Interface Adapter Pia
• Manufacturer: Western Design Center, Inc.

DATA
DDR
Figure 9A Port A, CA2 Buffers – W65C21N
Figure 10A Port A, CA2 Buffers – W65C21S
REGISTER
RS1
INPUT
SELECT
0
0
0
1
1
1
PIN
RS0
0
0
1
0
0
1
P
N
Table 2 Register Addressing
CONTROL BIT
CRA-
Table 1 Control Registers
DIRECTION
REGISTER
2
1
0
-
-
-
-
ACCESS
DATA
P
PIN
CRB-
2
1
0
-
-
-
-
REGISTER SELECTED
Peripheral Interface A
Data Direction Register A
Control Register A
Peripheral Interface B
Data Direction Register B
Control Register B
Figure 9B Port B, CB2 Buffers – W65C21N
Figure 10B Port B, CB2 Buffers – W65C21S
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