UPD6P8 NEC [NEC], UPD6P8 Datasheet - Page 19

• Manufacturer Part Number: UPD6P8
• Description: MOS INTEGRATED CIRCUIT 4-BIT SINGLE-CHIP MICROCONTROLLER FOR INFRARED REMOTE CONTROL TRANSMISSION
• Manufacturer: NEC [NEC]

4. PORT REGISTERS (PX)
The K
After reset, the port register values are as shown below.
Notes 1.
Remark V
I/O
2.
DP
port, the K
K
K
I/O7
0
I3
ID
11
: Refers to the value based on the K
: Refers to the value based on decrease of power supply voltage (0 when V
: RAM retention detection voltage
Note When in OFF mode, “1” is always read.
DP
K
I
K
K
S
S
S
K
port, the special ports (S
I/O6
0
Port Name
I2
I/O
I
0
1
2
10
/LED
Table 4-1. Relationship Between Ports and Reading/Writing
P
P
P
P
10
11
13
14
Pull-down
K
DP
K
K
I/O5
I1
I
9
Figure 4-1. Port Register Configuration
Pin state
Pin state
Pin state
Pin state
Pin state
P3 (control register 0)
P4 (control register 1)
Pull-down
Read
S
K
DP
K
0
Port register
I/O4
/S
I0
8
1
Input Mode
Data Sheet U17848EJ3V0DS
0
P0
P1
, S
STOP release
retention
S
1
RAM
/LED, S
K
1
Output latch
flag
/LED
S
I/O3
2
I
and S
Write
—
—
—
—
S
2
1
/LED mode
), and the control registers are treated as port registers.
2
K
S
I/O2
–
pin state.
0
Output latch
Note
Pin state
P
P
P
P
00
01
03
04
K
Read
I/O
K
—
—
S
mode S
I/O1
–
2
Output Mode
0
Output latch
K
mode
PD6P8, 6P8A, 6P8B
I/O0
1
–
Write
—
—
—
—
FFH
0000 000B
26H
11 1B
After reset
DD
Note 1
Note 2
V
ID
)
19