NEC 78K0S/KB1+ User Manual page 89

Caution 7. Changing the CR000 setting during TM00 operation may cause a malfunction. To change
the setting, refer to 6.5 Cautions Related to 16-bit Timer/Event Counter 00 (17) Changing
compare register during timer operation.
(3) 16-bit timer capture/compare register 010 (CR010)
CR010 is a 16-bit register which has the functions of both a capture register and a compare register. Whether
it is used as a capture register or a compare register is set by bit 2 (CRC002) of capture/compare control
register 00 (CRC00).
CR010 is set by 16-bit memory manipulation instruction.
Reset signal generation clears CR010 to 0000H.
Figure 6-4. Format of 16-bit Timer Capture/Compare Register 010 (CR010)
Address: FF16H, FF17H
Symbol
7 6
CR010
• When CR010 is used as a compare register
The value set in CR010 is constantly compared with the 16-bit timer counter 00 (TM00) count value, and an
interrupt request (INTTM010) is generated if they match.
• When CR010 is used as a capture register
It is possible to select the valid edge of the TI000 pin as the capture trigger. The TI000 valid edge is set by
means of prescaler mode register 00 (PRM00) (refer to Table 6-3).
Table 6-3. CR010 Capture Trigger and Valid Edge of TI000 Pin (CRC002 = 1)
CR010 Capture Trigger
Falling edge
Rising edge
Both rising and falling edges
Remarks 1. Setting ES010, ES000 = 1, 0 is prohibited.
2. ES010, ES000: Bits 5 and 4 of prescaler mode register 00 (PRM00)
CRC002:
Cautions 1. In the free-running mode and in the clear & start mode using the valid edge of the TI000
pin, if CR010 is set to 0000H, an interrupt request (INTTM010) is generated when CR010
changes from 0000H to 0001H following overflow (FFFFH).
2. If the new value of CR010 is less than the value of 16-bit timer counter 0 (TM00), TM00
continues counting, overflows, and then starts counting from 0 again. If the new value of
CR010 is less than the old value, therefore, the timer must be reset to be restarted after
the value of CR010 is changed.
3. The value of CR010 after 16-bit timer/event counter 00 has stopped is not guaranteed.
4. The capture operation may not be performed for CR010 set in compare mode even if a
capture trigger is input.
CHAPTER 6 16-BIT TIMER/EVENT COUNTER 00
After reset: 0000H R/W
FF17H
5 4 3 2 1 0
Falling edge
Rising edge
Both rising and falling edges
Bit 2 of capture/compare control register 00 (CRC00)
User's Manual U17446EJ3V1UD
FF16H
7 6 5 4 3 2
TI000 Pin Valid Edge
ES010
0
0
1
1 0
ES000
0
1
1
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