MC908QL4MDWE Freescale Semiconductor, MC908QL4MDWE Datasheet - Page 178

• Manufacturer Part Number: MC908QL4MDWE
• Description: IC MCU 8BIT 4K FLASH 16-SOIC
• Manufacturer: Freescale Semiconductor
• Series: HC08r

Specifications of MC908QL4MDWE

• Core Processor: HC08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: LIN (Local Interconnect Network)
• Peripherals: LVD, POR, PWM
• Number Of I /o: 13
• Program Memory Size: 4KB (4K x 8)
• Program Memory Type: FLASH
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Data Converters: A/D 6x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 16-SOIC (0.300", 7.5mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

Timer Interface Module (TIM)
15.3.4.3 PWM Initialization
To ensure correct operation when generating unbuffered or buffered PWM signals, use the following
initialization procedure:
Setting MS0B links channels 0 and 1 and configures them for buffered PWM operation. The TIM
channel 0 registers (TCH0H:TCH0L) initially control the buffered PWM output. TIM status control
register 0 (TSCR0) controls and monitors the PWM signal from the linked channels. MS0B takes priority
over MS0A.
Clearing the toggle-on-overflow bit, TOVx, inhibits output toggles on TIM overflows. Subsequent output
compares try to force the output to a state it is already in and have no effect. The result is a 0% duty cycle
output.
Setting the channel x maximum duty cycle bit (CHxMAX) and setting the TOVx bit generates a 100% duty
cycle output. See
178
1. In the TIM status and control register (TSC):
2. In the TIM counter modulo registers (TMODH:TMODL), write the value for the required PWM
3. In the TIM channel x registers (TCHxH:TCHxL), write the value for the required pulse width.
4. In TIM channel x status and control register (TSCx):
5. In the TIM status control register (TSC), clear the TIM stop bit, TSTOP.
period.
a. Stop the counter by setting the TIM stop bit, TSTOP.
b. Reset the counter and prescaler by setting the TIM reset bit, TRST.
a. Write 0:1 (for unbuffered output compare or PWM signals) or 1:0 (for buffered output compare
b. Write 1 to the toggle-on-overflow bit, TOVx.
c. Write 1:0 (polarity 1 — to clear output on compare) or 1:1 (polarity 0 — to set output on
or PWM signals) to the mode select bits, MSxB:MSxA. See
compare) to the edge/level select bits, ELSxB:ELSxA. The output action on compare must
force the output to the complement of the pulse width level. See
In buffered PWM signal generation, do not write new pulse width values to
the currently active channel registers. User software should track the
currently active channel to prevent writing a new value to the active
channel. Writing to the active channel registers is the same as generating
unbuffered PWM signals.
In PWM signal generation, do not program the PWM channel to toggle on
output compare. Toggling on output compare prevents reliable 0% duty
cycle generation and removes the ability of the channel to self-correct in the
event of software error or noise. Toggling on output compare can also
cause incorrect PWM signal generation when changing the PWM pulse
width to a new, much larger value.
15.8.1 TIM Status and Control
MC68HC908QL4 Data Sheet, Rev. 8
NOTE
NOTE
Register.
Table
Table
15-2.
15-2.
Freescale Semiconductor