sh66k51a SinoWealth Micro-Electronics Corp. Ltd, sh66k51a Datasheet - Page 16

• Manufacturer Part Number: sh66k51a
• Description: 2k 4-bit Micro-controller With Lcd Driver
• Manufacturer: SinoWealth Micro-Electronics Corp. Ltd

6. I/O PORT
The SH66K51A provides 18 bi-directional I/O ports. The PORT data put in register $08 - $0C. The PORT control register
($18 - $1C) controls the PORT as input or output. Each I/O port has an internal pull-high resistor, which is controlled by
PULLEN of $13 and the data of the port, when the PORT is used as input.
System Register $08 - $0C, $18 - $1C (Port data register and control register)
PA (/B/C/D) CR.n, (n = 0, 1, 2, 3), PECR.n (n = 0, 1)
1: Set I/O as an output buffer.
0: Set I/O as an input buffer (default).
Equivalent Circuit for a Single I/O Pin:
Address
$0A
$0B
$0C
$1A
$1B
$1C
$08
$09
$18
$19
PULLEN
PACR.3
PBCR.3
PCCR.3
PDCR.3
PC.3
PD.3
PA.3
PB.3
Bit3
-
-
I/O Control
Register
Regiser
DATA
DATA
PBCR.2
PCCR.2
PDCR.2
PACR.2
PB.2
PC.2
PD.2
PA.2
Bit2
-
-
Port Configuration Function Block Diagram
PBCR.1
PCCR.1
PDCR.1
PECR.1
PACR.1
PC.1
PD.1
PA.1
PB.1
PE.1
Bit1
READ DATA IN
PCCR.0
PDCR.0
PACR.0
PBCR.0
PECR.0
PB.0
PC.0
PD.0
PE.0
PA.0
Bit0
READ
16
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
PORTB input/output control
PORTC input/output control
PORTD input/output control
PORTE input/output control
PORTA input/output control
GND
V
DD
Remarks
PORTB
PORTC
PORTD
PORTE
PORTA
V
DD
Pull high
Weak
I/O pin
SH66K51A