gc80c520a CORERIVER Semiconductor, gc80c520a Datasheet - Page 170

• Manufacturer Part Number: gc80c520a
• Description: Midas1.0 Family Mask Rom/eprom/romless 8-bit Turbo Microcontrollers
• Manufacturer: CORERIVER Semiconductor

15.21 Slave Address Register (SADDR)
The register is programmed with the given or broadcast address assigned to serial port.
15.22 Port 3 Register (P3)
This register functions as a general purpose I/O port. In addition, all the pins have an alternative function
listed below. Each of the functions is controlled by other SFRs. The associated Port 3 latch bit must
contain in a logic one before the pin can be used in its alternative function capacity.
Bit No.
Bit No.
A9h
B0h
Symbol
/INT1
/INT0
/WR
TXD
RXD
/RD
T1
T0
R/W(0)
R/W(1)
SADDR.7
P3.7
/RD
7
7
Function
External Data Memory Read Strobe. This pin provides an active low read strobe to an
external memory device.
External Data Memory Write Strobe. This pin provides an active low write strobe to an
external memory device.
Timer/Counter 1 External Input. A 1-to-0 transition on this pin will increment Timer 1.
Timer/Counter 0 External Input. A 1-to-0 transition on this pin will increment Timer 0.
Serial Port Receive. This pin receives the serial port data in serial port modes 1,2,3 and
is a bi-directional data transfer pin in serial port mode 0.
External Interrupt 1. A falling edge/low level on this pin will cause an external interrupt
1 if enabled.
External Interrupt 0. A falling edge/low level on this pin will cause an external interrupt
0 if enabled.
Serial Port Transmit. This pin transmits the serial port data in serial port modes 1,2,3
and emits the synchronizing clock in serial port mode 0.
SADDR.6
R/W(0)
R/W(1)
P3.6
/WR
6
6
SADDR.5
R/W(0)
R/W(1)
P3.5
T1
5
5
SADDR.4
R/W(0)
R/W(1)
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P3.4
T0
4
4
SADDR.3
R/W(0)
R/W(1)
/INT1
P3.3
3
3
R/W(0)
R/W(1)
SADDR.2
/INT0
P3.2
2
2
Appendix B: SFR description
SADDR.1
R/W(0)
R/W(1)
P3.1
TXD
1
1
SADDR.0
R/W(0)
R/W(1)
P3.0
RXD
0
0
SADDR
P3