Format Of Carrier Generator Output Control Register 40 - NEC PD789860 User Manual

(3) Carrier generator output control register 40 (TCA40)
TCA40 is used to set the timer output data in the carrier generator mode.
This register is set with an 8-bit memory manipulation instruction.
RESET input clears this register to 00H.
Figure 9-6. Format of Carrier Generator Output Control Register 40
Symbol 7 6
TCA40 0 0
RMC40
0 When NRZ40 = 1, a carrier pulse is output to the TMO/P20/BSFO pin
1 When NRZ40 = 1, a high level is output to the TMO/P20/BSFO pin
NRZB40 This bit stores the data that NRZ40 will output next. Data is transferred to NRZ40 upon the generation of a
timer 30 match signal. Input the necessary value in NRZB40 in advance by program.
NRZ40
0 A low level is output (the carrier clock is stopped)
1 A carrier pulse or high level is output
Cautions 1. Be sure to clear bits 3 to 7 to 0.
2. TCA40 cannot be set with a 1-bit memory manipulation instruction. Be sure to use an 8-
bit memory manipulation instruction to set TCA40.
3. The NRZ40 flag can be written only when carrier generator output is stopped (TOE40 =
0). The data cannot be overwritten when TOE40 = 1.
4. When the carrier generator is stopped once and then started again, NRZB40 does not
hold the previous data.
manipulation instruction must not be used.
manipulation instruction.
5. To enable operation in the carrier generator mode, set a value to the compare registers
(CR30, CR40, and CRH40), and input the necessary value to the NRZB40 and NRZ40 flags
in advance. Otherwise, the signal of the timer match circuit will become unstable and
the NRZ40 flag will be undefined.
6. Note that the
apply to the mask ROM version and the
(a) While INTTM30 (interrupt generated by the match signal of timer 30) is being output,
accessing TCA40 is prohibited.
(b) Accessing TCA40 is prohibited while 8-bit timer counter 30 (TM30) is 00H.
To access TCA40 while TM30 = 00H, wait for more than half a period of the TM30
count clock and then rewrite TCA40.
CHAPTER 9 8-BIT TIMERS 30 AND 40
5 4 3
0 0 0 RMC40
Remote controller output control
No return zero data
Re-set data to NRZB40.
µ
PD78E9860 and 78E9861 have the following restrictions (which do not
User's Manual U14826EJ5V0UD
2 1 0 Address After reset
NRZB40 NRZ40
At this time, a 1-bit memory
Be sure to use an 8-bit memory
µ
PD78E9860A and 78E9861A).
R/W
FF57H 00H W
91