tmp89fm42 TOSHIBA Semiconductor CORPORATION, tmp89fm42 Datasheet - Page 208

• Manufacturer Part Number: tmp89fm42
• Description: 8 Bit Microcontroller
• Manufacturer: TOSHIBA Semiconductor CORPORATION

14. 8-bit Timer Counter (TC0)
RA002
Timer register 00
Timer register 01
14.4.7 12-bit pulse width modulation (PWM) output mode
T00PWM
T01PWM
(0x0028)
(0x0029)
14.4.7.1 Setting
with a resolution of 8 bits. An additional pulse of 4 bits can be inserted, which enables PWM output with a res-
olution nearly equivalent to 12 bits.
In the 12-bit PWM output mode, TC00 and TC01 are cascaded to output the pulse-width modulated pulses
Read/Write
Read/Write
settings of TC00 are ignored and those of TC01 are effective in the 16-bit timer mode.
source clock, set T01MOD<EIN1> to "0" and select the clock at T01MOD<TCK1>. To use an external
clock as the source clock, set T01MOD<EIN1> to "1".
becomes invalid. Be sure to complete the required mode settings before starting the timer. (Make settings
when T001CR<T00RUN> and <T01RUN> are "0".)
the timer registers T00PWM and T01PWM. Set bits 11 to 8 of the 12-bit value at the lower 4 bits of
T01PWM and set bits 7 to 0 at T00PWM. Refer to the following table for the register configuration. Here-
inafter, the 12-bit value specified by the combined setting of T00PWM and T01PWM is indicated as
T01+00PWM. The timer register settings are reflected on the double buffer or T01+00PWM when a write
instruction is executed on T01PWM. Be sure to execute the write instructions on T00PWM and T01PWM
in this order. (When data is written to the high-order register, the set values of the low-order and high-
order registers become effective at the same time.)
Bit Symbol
Bit Symbol
bits of T01PWM and the written values are read out as they are when the bits are read. Normally, set these
bits to "0".
pulse width (time before the first change in the output) for one cycle (256 counts of the source clock).
Hereinafter, an 8-bit value specified by the combined setting of PWMDUTYH and PWMDUTYL is indi-
cated as PWMDUTY.
cycles of the duty pulse by setting each bit to "1". The additional pulses are inserted in the positions listed
in Table 14-10. PWMAD 3 to 0 can be combined to specify the number of times of inserting the additional
pulses in 16 cycles to any number from 1 to 16. Examples of inserting additional pulses are shown in Fig-
ure 14-13.
After reset
After reset
Setting T001CR<TCAS> to "1" connects TC00 and TC01 and activates the 16-bit timer mode. All the
The 12-bit PWM mode is selected by setting T01MOD<TCM1> to "10". To use the internal clock as the
Set T01MOD<DBE1> to "1" to use the double buffer.
Setting T001CR<T01RUN> to "1" starts the operation. After the timer is started, writing to T01MOD
Set the count value to be used for the match detection and the additional pulse value as a 12-bit value at
Bits 7 to 4 of T01PWM are not used in the 12-bit PWM mode. However, data can be written to these
PWMDUTYH and PWMDUTYL are 4-bit registers. They are combined to set an 8-bit value of duty
PWMAD3 to 0 are the additional pulse setting register. Additional pulses can be inserted in specific
R/W
7
1
7
1
R/W
6
1
6
1
PWMDUTYL
R/W
5
1
5
1
Page 194
R/W
4
1
4
1
PWMAD3
R/W
R/W
3
1
3
1
PWMAD2
R/W
R/W
2
1
2
1
PWMDUTYH
PWMAD1
R/W
R/W
1
1
1
1
TMP89FM42
PWMAD0
R/W
R/W
0
1
0
1