em78p134n ELAN Microelectronics Corp, em78p134n Datasheet - Page 40

• Manufacturer Part Number: em78p134n
• Description: 8-bit Microcontroller With Otp Rom
• Manufacturer: ELAN Microelectronics Corp

EM78P134N
8-Bit Microcontroller with OTP ROM
34 •
5.7.2 Increment Timer Counter (TMRX: TMRH/TMRL)
TMRX are 10-bit clock counters with programmable prescalers. They are designed for
the PWM module as baud rate clock generators. TMRX can be read only. If employed,
they can be turned off for power saving by setting the T1EN Bit [RB<3>] to 0.
5.7.3 PWM Time Period (PRDX: TMRH/PRDL)
The PWM time period is defined by writing to the PRDL register. When TMRX is equal
to PRDX, the following events occur on the next increment cycle:
The following formula describes how to calculate the PWM Time Period:
Example:
PRDX = 49;
Then
TMRX is cleared
The PWMX pin is set to 1
The PWM duty cycle is latched from DT to DTL
The PWMIF pin is set to 1
Period
=
The PWM output will not be set, if the duty cycle is 0
Period
(
PRDX
Fosc = 4 MHz;
Figure 5-13 PWM Output Timing
=
+
1
(
49
)
×
+
(This specification is subject to change without further notice)
1
⎛
⎜ ⎜
⎝
)
NOTE
F
×
OSC
1
⎛
⎜
⎝
⎞
⎟ ⎟
⎠
4
1
M
TMRX (0, 0, 0) = 1 : 1,
Product Specification (V1.6) 06.02.2010
×
⎞
⎟
⎠
(
TMRX
×
=
12
prescale
5 .
μs
value
)