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CHAPTER 7 8-BIT TIMERS 50, 60
User’s Manual U15075EJ2V1UD
149
Cautions 1. Bits 3 to 7 must be set to 0.
2. TCA60 cannot be set with a 1-bit memory manipulation instruction. Be sure to use an 8-
bit memory manipulation instruction to set TCA60.
3. The NRZ60 flag can be written only when carrier generator output is stopped (TOE60 =
0). The data cannot be overwritten when TOE60 = 1.
4. When the carrier generator is stopped once and then started again, NRZB60 does not
hold the previous data. Re-set data to NRZB60. At this time, a 1-bit memory
manipulation instruction must not be used. Be sure to use an 8-bit memory
manipulation instruction.
5. While INTTM50 (interrupt generated by the match signal of timer 50) is being output,
accessing TCA60 is prohibited.
6. Accessing TCA60 is prohibited while 8-bit timer counter 50 (TM50) is 00H.
To access TCA60 while TM50 = 00H, wait for more than half a period of the TM50 count
clock and then rewrite TCA60.
7. To enable operation in the carrier generator mode, set a value to the compare registers
(CR50, CR60, and CRH60), and input the necessary value to the NRZB60 and NRZ60
flags in advance. Otherwise, the signal of the timer match circuit will become unstable
and the NRZ60 flag will be undefined.
(4) Port mode register 3 (PM3)
This register is used to set the I/O mode of port 3 in 1-bit units.
When using the P31/TO50/INTP1/TMI60 pin as a timer output, set PM31 and the P31 output latch to 0.
When using the P31/TO50/INTP1/TMI60 pin as a timer input, set PM31 to 1.
When using the P32/TO60/INTP2 pin as a timer output, set the PM32 and P32 output latch to 0.
When using the P33/TO61/INTP3 pin as a timer output, set the PM33 and P33 output latch to 0.
PM3 is set with a 1-bit or 8-bit memory manipulation instruction.
RESET input sets PM3 to FFH.
Figure 7-7. Format of Port Mode Register 3
Symbol
7 6 5 4 3 2 1 0
Address
After
reset
R/W
PM3
1 1 1 1
PM33
PM32
PM31
PM30
FF23H
FFH
R/W
PM3n
I/O mode of P3n pin
(n = 0 to 3)
0
Output mode (output buffer is ON)
1
Input mode (output buffer is OFF)