NEC mPD780973 Series, Preliminary User'S Manual

Page: 102 / 301

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CHAPTER 7 16-BIT TIMER 0 TM0
7.3 16-Bit Timer 0 Configuration
Timer 0 consists of the following hardware.
Table 7-2. Timer 0 Configuration
Item Configuration
Timer register 16 bits
×
1 (TM0)
Register Capture register: 16 bits
×
3 (CR00 to CR02)
Control register 16-bit timer mode control register (TMC0)
Capture pulse control register (CRC0)
Prescaler mode register (PRM0)
(1) 16-bit timer register (TM0)
TM0 is a 16-bit read-only register that counts count pulses.
The counter is incremented in synchronization with the rising edge of an input clock. If the count value is read
during operation, input of the count clock is temporarily stopped, and the count value at that point is read. The
count value is reset to 0000H in the following cases:
<1> At RESET input
<2> If TMC02 is cleared
(2) Capture register 00 (CR00)
The valid edge of the TI00 pin can be selected as the capture trigger. Setting of the TI00 valid edge is performed
by setting of the prescaler mode register (PRM0). When the valid edge of the TI00 is detected, an interrupt request
(INTTM00) is generated.
CR00 is read by a 16-bit memory manipulation instruction.
After RESET input, the value of CR00 is undefined.
(3) Capture register 01 (CR01)
The valid edge of the TI01 pin can be selected as the capture trigger. Setting of the TI01 valid edge is performed
by setting of the prescaler mode register (PRM0). When the valid edge of the TI01 is detected, an interrupt request
(INTTM01) is generated.
CR01 is read by a 16-bit memory manipulation instruction.
After RESET input, the value of CR01 is undefined.
(4) Capture register 02 (CR02)
The valid edge of the TI02 pin can be selected as the capture trigger. Setting of the TI02 valid edge is performed
by setting of the prescaler mode register (PRM0). When the valid edge of the TI02 is detected, an interrupt request
(INTTM02) is generated.
CR02 is read by a 16-bit memory manipulation instruction.
After RESET input, the value of CR02 is undefined.