UPD6600A NEC, UPD6600A Datasheet - Page 12

• Manufacturer Part Number: UPD6600A
• Description: 4-BIT SINGLE-CHIP MICROCONTROLLER FOR REMOTE CONTROL TRANSMISSION
• Manufacturer: NEC

12
12. PORT REGISTER (P )
Name
S-IN
K
Pin
K
The table below shows the relations between the port registers and pins.
K
I/O
I/O
I
, K
Pin status is read by RL A instruction when D
I
, and the control register are handled as port registers.
Pin status
Pin status
Read
Input Mode
Table 12-1. Relations between Port Registers and Pins
Output latch
P
P
P
Write
11
10
12
–
Control register (H)
K
K
P
1
I/O7-4
I3-0
(H)
Pin status
Read
0
–
of P
Output Mode
1
register = 1.
P
P
P
01
00
02
Control register (L)
Output latch
P
Write
K
0
–
I/O3-0
(L)
High impedance (D
Undefined [input mode, output latch]
Input mode
P
P
P
0
1
2
PD6124A, 6600A
On Reset
0
of P
1
register = 0)