sh66p51 SinoWealth Micro-Electronics Corp. Ltd, sh66p51 Datasheet - Page 20

• Manufacturer Part Number: sh66p51
• Description: Otp 2k 4-bit Micro-controller With Lcd Driver
• Manufacturer: SinoWealth Micro-Electronics Corp. Ltd

Key Matrix’s IO Ports Control Register
PAIN…PEIN: In the key matrix’s application, control PORTA - PORTE input and output access.
0: Enable PORTA - PORTE pull-high resistor and I/O access, Ports in normal state
1: Disable PORTA - PORTE pull-high resistor and its I/O access
Port Interrupt
The PORTB and PORTC are used as port interrupt sources. Since PORT I/O is bit programmable I/O, so only the input port
can generate an external interrupt. Any one of the PORTB and PORTC input pin transitions from V
generate an interrupt request. Further falling edge transition would not be able to make an interrupt request until all of the
input pins have returned to V
Address
$16
$17
PAIN
Bit 3
-
PORTC.n
PORTB.n
PBIN
Bit 2
-
DD
Note: n = 0, 1, 2, 3
PBCR.n
PCCR.n
. The following is the port interrupts function block-diagram.
PCIN
Bit 1
-
Figure 4. PORT Interrupt Block Diagram
PDIN
PEIN
Bit 0
R/W
R/W
R/W
Edge Detector
20
Falling
Control PORTA - PORTD input and output access enable
or disable. Used in key matrix’s application
Control PORTE input and output access enable or
disable. Used in key matrix’s application
IEP
IRQP
Remarks
Port Interrupt
DD
to GND would
SH66P51