W741E20X Datasheet, PDF (15/84 Pages) Winbond – 4-BIT FLASH MICROCONTROLLER

Preliminary W741E20X
Port Mode 0 Register (PM0)
The port mode 0 register is organized as 4-bit binary register (PM0.0 to PM0.3). PM0 can be used to
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
ww
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 0 = 1 RB port is NMOS open drain output type.
Bit 2 & Bit 3 are reserved.
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:
3 210
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).
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:
3 210
PM2 w w w w
Note: W means write only.
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Publication Release Date: March 1998
Revision A1