upd63a Renesas Electronics Corporation., upd63a Datasheet - Page 18

• Manufacturer Part Number: upd63a
• Description: 4-bit Single-chip Microcontroller For Infrared Remote Control Transmission
• Manufacturer: Renesas Electronics Corporation.

3.4 Control Register 1 (P4)
18
Control register 1 consists of 8 bits. The contents that can be controlled are as shown below.
When reset, the register becomes 0010 0110B.
b
b
b
b
b
Remark In OUTPUT mode or in OFF mode, all the pull-down resistors are automatically disconnected.
0
1
2
4
5
: Specifies the input mode of the S
: Specifies the I/O mode of the K
: Specifies the I/O mode of the S
: Specifies the availability of the pull-down resistor in S
: Specifies the availability of the pull-down resistor in K
“0” = IN (INPUT mode); “1” = OUT (OUTPUT mode).
“1” = ON (available)
“1” = ON (available).
Bit
Name
Set
value
When reset
0
1
b
Fixed
to “0”
0
7
—
Table 3-6. Control Register 1 (P4)
b
Fixed
to “0”
0
6
I/O
1
—
/LED port. “0” = S
0
port.
port. “0” = OFF mode (high impedance); “1” = IN (INPUT mode).
Pull-down Pull-down
b
K
OFF
ON
1
5
I
b
S
OFF
ON
0
4
0
/S
1
1
(INPUT mode); “1” = LED (output mode).
0
I
/S
port. “0” = OFF (unavailable);
b
Fixed
to “0”
0
3
1
—
port INPUT mode. “0” = OFF (unavailable);
b
S
mode
S
LED
1
2
1
1
/LED
b
K
mode
IN
OUT
1
1
I/O
b
S
mode
OFF
IN
0
0
0
PD63, 63A, 64