sh66l06a SinoWealth Micro-Electronics Corp. Ltd, sh66l06a Datasheet - Page 8

• Manufacturer Part Number: sh66l06a
• Description: 1k 4-bit Micro-controller With Lcd Driver
• Manufacturer: SinoWealth Micro-Electronics Corp. Ltd

6. I/O Port
The MCU provides 8 bi-directional I/O ports. The PORT data is put in register $08 - $09. The PORT control register ($1B - $1C)
controls the PORT as input or output. Each I/O port has an internal pull-high resistor, which is controlled by PPULL of $15 and
the data of the PORT, when the PORT is used as input.
Port I/O mapping address is shown as follows:
PA (/B) CR.n, (n = 0, 1, 2, 3)
0: Set I/O as an input direction. (Power on initial)
1: Set I/O as an output direction.
Equivalent Circuit for a Single I/O Pad
When PAM = 1 (System register $13 Bit0), PORTA.1 - 2 are used as Alarm output.
Address
$1B
$1C
$08
$09
PACR.3
PBCR.3
PPULL
PA.3
PB.3
Bit3
I/O Control
Register
Register
DATA
PACR.2
PBCR.2
DATA
PA.2
PB.2
Bit2
PACR.1
PBCR.1
PA.1
PB.1
Bit1
READ DATA IN
PACR.0
PBCR.0
PA.0
PB.0
Bit0
READ
R/W
R/W
R/W
R/W
R/W
8
PORTA data register
PORTB data register
PORTA input/output control register
PORTB input/output control register
GND
V
DD
Remarks
V
DD
Weak Pull high
I/O Pad
SH66L06A