NEC 78K0 User Manual page 183

Figure 8-5. Format of 8-Bit Timer H Mode Register 0 (TMHMD0)
Address: FF69H
TMHMD0 TMHE0
TMHE0
CKS02
TMMD01
Other than above
TOLEV0
TOEN0
Note To select the TM50 output as a count clock, start operation by setting 8-bit timer/event counter 50 in the
PWM output mode (bit 6 (TMC506) of the TMC50 register = 1), and then set CKS02, CKS01, and CKS00 to
1, 0, and 1, respectively. Set the high-/low-level width of the count clock so that the specifications of the
input width of TI50 are satisfied (see AC Characteristics (1) Basic operation in CHAPTER 25 to
CHAPTER 27). It is not necessary to enable the TO50 pin as a timer output pin (bit 0 (TOE50) of the TMC
register may be 0 or 1).
Cautions 1. When the Ring-OSC clock is selected as the clock to be supplied to the CPU, the clock of the
Ring-OSC oscillator is divided and supplied as the count clock. If the count clock is the
Ring-OSC clock, the operation of 8-bit timer H0 is not guaranteed.
2. When TMHE0 = 1, setting the other bits of the TMHMD0 register is prohibited.
3. In the PWM output mode, be sure to set 8-bit timer H compare register 10 (CMP10) when
starting the timer count operation (TMHE0 = 1) after the timer count operation was stopped
(TMHE0 = 0) (be sure to set again even if setting the same value to the CMP10 register).
CHAPTER 8 8-BIT TIMERS H0 AND H1
After reset: 00H R/W
<7> 5
6
CKS02 CKS01
0
Stops timer count operation (counter is cleared to 0)
1 Enables timer count operation (count operation started by inputting clock)
CKS01 CKS00
0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
Other than above
TMMD00
0 0
Interval timer mode
1 0 PWM output mode
Setting prohibited
Timer output level control (in default mode)
0 Low level
1
High level
0 Disables output
1
Enables output
User's Manual U16227EJ2V0UD
3 2
4
CKS00 TMMD01 TMMD00 TOLEV0
Timer operation enable
Count clock (f ) selection
CNT
f (10 MHz)
X
f /2 (5 MHz)
X
2
(2.5 MHz)
f /2
X
6
f /2 (156.25 kHz)
X
10
f /2 (9.77 kHz)
X
Note
TM50 output
Setting prohibited
Timer operation mode
Timer output control
<1> <0>
TOEN0
183