Freescale Semiconductor MC68HC908MR32 Manual Do Utilizador
Control Logic Block
MC68HC908MR32 • MC68HC908MR16 Data Sheet, Rev. 6.1
Freescale Semiconductor
145
12.9.3 PWMx Value Registers
Each of the six PWMs has a 16-bit PWM value register.
The 16-bit signed value stored in this register determines the duty cycle of the PWM. The duty cycle is
defined as: (PWM value/modulus) x 100.
defined as: (PWM value/modulus) x 100.
Writing a number less than or equal to 0 causes the PWM to be off for the entire PWM period. Writing a
number greater than or equal to the 12-bit modulus causes the PWM to be on for the entire PWM period.
number greater than or equal to the 12-bit modulus causes the PWM to be on for the entire PWM period.
If the complementary mode is selected, the PWM pairs share PWM value registers.
To avoid erroneous PWM pulses, this value is buffered and will not be used by the PWM generator until
the LDOK bit has been set and the next PWM load cycle begins.
the LDOK bit has been set and the next PWM load cycle begins.
NOTE
When reading these registers, the value read is the buffer (not necessarily
the value the PWM generator is currently using).
the value the PWM generator is currently using).
Bit 7
6
5
4
3
2
1
Bit 0
Read:
Bit 15
Bit 14
Bit 13
Bit 12
Bit 11
Bit 10
Bit 9
Bit 8
Write:
Reset:
0
0
0
0
0
0
0
0
Bold
= Buffered
Figure 12-37. PWMx Value Registers High (PVALxH)
Bit 7
6
5
4
3
2
1
Bit 0
Read:
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Write:
Reset:
0
0
0
0
0
0
0
0
Bold
= Buffered
Figure 12-38. PWMx Value Registers Low (PVALxL)