W742E Datasheet, PDF (41/60 Pages) Winbond – 4 BIT MICROCONTROLLER

W742E/C811
Bit 0 = 1
Bit 1 = 1
Bit 2 = 1
Bit 3 = 1
Signal change at RD.0
Signal change at RD.1
Signal change at RD.2
Signal change at RD.3
5.21 Output Port RE & RF
Output port RE and RF are used as output of the internal RT port. When the MOV RE, R or MOV RF,
R instruction is executed, the data in the RAM will be output to port RT through port RE or RF. They
provide high sink current to drive LED.
5.22 Input Port P1
Input port P1 is a multi-function input port. When the MOVA R, P1 instruction is executed, the P1 data
will be get to the RAM and A register. The P1.2 and P1.3 can be configurated as the external interrupt
/INT0 and /INT1 by set P1EF.2 and P1EF.3.
5.23 DTMF Output Pin (DTMF)
W742E/C811 provides a DTMF generator which outputs the dual tone multi-frequency signal to the
DTMF pin. The DTMF generator can work well at the operating frequency of 3.58 MHz. A DTMF
register specify the desired low/high frequency. And the Dual Tone Control Register (DTCR) can
control whether the dual tone will be output or not. The tones are divided into two groups (low group
and high group). The relation between the DTMF signal and the corresponding touch tone keypad is
shown in Figure 5-16.
C1 ^{C2 C3 C4}
R1 1 2 3 A
R2 4 5 6 B
R3 7 8 9 C
R4 _* 0 # D
Row/Col
R1
R2
R3
R4
C1
C2
C3
C4
Frequency
697 Hz
770 Hz
852 Hz
941 Hz
1209 Hz
1336 Hz
1477 Hz
1633 Hz
Figure 5-16 The relation between the touch tone keypad and the frequency
- 41 -
Publication Release Date: December 2000
Revision A1