W742S81A Datasheet, PDF (27/47 Pages) Winbond – 4 BIT MICROCONTROLLER

W742S81A
determine the structure of the input/output ports; it is controlled by the MOV PM0, #I instruction. The bit
descriptions are as follows:
3210
PM0 w w w w
Note: W means write only.
Bit 0 = 0 RA port is CMOS output type. Bit 0 = 1 RA port is NMOS open drain output type.
Bit 1 = 0 RB port is CMOS output type. Bit 1 = 1 RB port is NMOS open drain output type.
Bit 2 = 0 RC port pull-high resistor is disabled. Bit 2 = 1 RC port pull-high resistor is enabled.
Bit 3 is reserved.
6.17.2 Port Mode 1 Register (PM1)
The port mode 1 register is organized as 4-bit binary register (PM1.0 to PM1.3). PM1 can be used to
control the input/output mode of port RA. PM1 is controlled by the MOV PM1, #I instruction. The bit
descriptions are as follows:
3210
PM1 w w w w
Note: W means write only.
Bit 0 = 0 RA.0 works as output pin; Bit 0 = 1 RA.0 works as input pin
Bit 1 = 0 RA.1 works as output pin; Bit 1 = 1 RA.1 works as input pin
Bit 2 = 0 RA.2 works as output pin; Bit 2 = 1 RA.2 works as input pin
Bit 3 = 0 RA.3 works as output pin; Bit 3 = 1 RA.3 works as input pin
At initial reset, port RA is input mode (PM1 = 1111B).
6.17.3 Port Mode 2 Register (PM2)
The port mode 2 register is organized as 4-bit binary register (PM2.0 to PM2.3). PM2 can be used to
control the input/output mode of port RB. PM2 is controlled by the MOV PM2, #I instruction. The bit
descriptions are as follows:
3210
PM2 w w w w
Note: W means write only.
Bit 0 = 0
Bit 1 = 0
Bit 2 = 0
RB.0 works as output pin; Bit 0 = 1
RB.1 works as output pin; Bit 1 = 1
RB.2 works as output pin; Bit 2 = 1
RB.0 works as input pin
RB.1 works as input pin
RB.2 works as input pin
Publication Release Date: March 2003
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Revision A1