W741E20X Datasheet, PDF (14/84 Pages) Winbond – 4-BIT FLASH MICROCONTROLLER

Preliminary W741E20X
Mode Register 1 (MR1)
Mode Register 1 is organized as a 4-bit binary register (MR1.0 to MR1.3). MR1 can be used to control
the operation of Timer 1. The bit descriptions are as follows:
3
2
1
0
MR1 W W W W
Note: W means write only.
Bit 0 = 0 The internal fundamental frequency of Timer 1 is Fosc.
= 1 The internal fundamental frequency of Timer 1 is Fosc/64.
Bit 1 = 0 The fundamental frequency source of Timer 1 is the internal clock.
= 1 The fundamental frequency source of Timer 1 is the external clock from RC.0 input pin.
Bit 2 = 0 The specified waveform of the MFP generator is delivered at the MFP output pin.
= 1 The specified frequency of Timer 1 is delivered at the MFP output pin.
Bit 3 = 0 Timer 1 stops down-counting.
= 1 Timer 1 starts down-counting.
Input/Output Ports RA, RB
Port RA consists of pins RA.0 to RA.3 and Port RB consists of pins RB.0 to RB.3. At initial reset,
input/output ports RA and RB are both in input mode. When RA and RB are used as output ports,
CMOS or NMOS open drain output type can be selected by the PM0 register. Each pin of port RA or
RB can be specified as input or output mode independently by the PM1 and PM2 registers. The MOVA
R, RA or MOVA R, RB instructions operate the input functions and the MOV RA, R or MOV RB, R
operate the output functions. For more details, refer to the instruction table and Figure 7.
Input/Output Pin of the RA(RB)
PM0.0 (or PM0.1)
Vdd
DATA
BUS
Output
Buffer
Enable
MOV RA, R
(or MOV RB, R)
Instruction
PM1.n
(or PM2.n)
Enable
MOVA R, RA
(or MOVA R, RB)
instruction
Figure 7. Architecture of RA & RB Input/Output Pins
I/O PIN
RA.n(RB.n)
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