W541C250 Datasheet, PDF (6/10 Pages) Winbond – 4-BIT MICROCONTROLLER

W541C250
5. PIN DESCRIPTION
SYMBOL
XIN
XOUT
RA0−RA3
RB0−RB3
RC0−RC3
RD0−RD3
RE0−RE3
MFP
INT
RES
SEG0−SEG23
I/O
FUNCTION
Input pin for oscillator.
I Connected to crystal or resistor to generate system clock by code option.
External 10~20pF capacitor uses to get accurate freq in crystal mode.
Output pin for oscillator.
O _{Connected to crystal or resistor to generate system clock by code option.}
20PF capacitor is built in internal for crystal mode.
I/O
Input/Output port.
Input/output mode specified by port mode 1 register (PM1).
I/O
Input/Output port.
Input/output mode specified by port mode 2 register (PM2).
4-bit port for input only.
I Each pin has an independent interrupt capability. And build-in schmitt
trigger
I 4-bit port for input only.
O
Output port only.
This port provides high sink current to drive LEDs.
Output pin only.
O
This pin can output modulating or nonmodulating frequency, or Timer 1
clock output specified by mode register 1 (MR1).
I External interrupt pin with pull-high resistor.
I System reset pin with pull-high resistor.
O
LCD segment output pins.
Can also be used as DC output ports specified by code option.
LCD common signal output pins.
COM0−COM3 O
COM0
COM1
COM2
COM3
Static
Used
Not Used
Not Used
Not Used
1/2 Duty
Used
Used
Not Used
Not Used
1/3 Duty
Used
Used
Used
Not Used
1/4 Duty
Used
Used
Used
Used
The LCD alternating frequency can be selected by code option.
DH1, DH2
V_DD1, V_DD2
V_DD3
V_DD
VSS
I Connection terminals for voltage doubler (halver) capacitor.
Positive (+) supply voltage terminal.
I _{Refer to Functional Description.}
I Positive power supply (+).
I Negative power supply (-).
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