UPD6P9 datasheet(26/73 Pages) RENESAS

26 / 73 page

µPD67, 67A, 68, 68A, 69

Data Sheet U14935EJ2V1DS

4.3.2 Carrier output control

Remote controller carrier can be output from the REM pin by clearing (0) bit 9 (CARY) of the modulo register

for setting the high-level period (MOD1).

When performing carrier output, be sure to set the timer operation after setting the MOD0 and MOD1 values.

Note that a malfunction may occur if the values of MOD0 and MOD1 are changed while carrier is being output from

the REM pin.

Executing the timer manipulation instruction starts the carrier output from the low level.

If the timer’s down counter reaches 0 during carrier output, carrier output is stopped and the REM pin becomes

low level. If the down counter reaches 0 while the carrier output is high level, carrier output will stop after first

becoming low level following the set period of high level.

Figure 4-4. Timer Output (When Carrier Is Output)

(a)

µPD67, 68, and 69

(b)

µPD67A and 68A

Notes 1. If the down counter reaches 0 while the carrier output is high level, carrier output will stop after

becoming low level.

2. As shown in figure (b) above, in the

µPD67A and 68A, because the timer output time is 4/fX shorter

µs: fX = 4 MHz) than in the µPD67, 68, and 69, the down counter reaches 0 while the carrier output

is low level, so the carrier may be one clock shorter than in the

µPD67, 68, and 69.

Timer output time: (Set value+1)

× 64/fX

LED

REM

Note 1

Timer manipulation instruction

Timer output time: (Set value+1)

× 64/fX – 4/fX

LED

REM

Note 2

Timer manipulation instruction

4/fX

UPD6P9 Datasheet(PDF) 26 Page - Renesas Technology Corp