Datasheet

Pulse-Width Modulator (S12PWM8B8CV2)
MC9S12G Family Reference Manual, Rev.1.23
Freescale Semiconductor 647
19.3.2.6 PWM Control Register (PWMCTL)
The PWMCTL register provides for various control of the PWM module.
Read: Anytime
Write: Anytime
There are up to four control bits for concatenation, each of which is used to concatenate a pair of PWM
channels into one 16-bit channel. If the corresponding channels do not exist on a particular derivative, then
writes to these bits have no effect and reads will return zeroes. When channels 6 and 7are concatenated,
channel 6 registers become the high order bytes of the double byte channel. When channels 4 and 5 are
concatenated, channel 4 registers become the high order bytes of the double byte channel. When channels
2 and 3 are concatenated, channel 2 registers become the high order bytes of the double byte channel.
When channels 0 and 1 are concatenated, channel 0 registers become the high order bytes of the double
byte channel.
See Section 19.4.2.7, “PWM 16-Bit Functions” for a more detailed description of the concatenation PWM
Function.
NOTE
Change these bits only when both corresponding channels are disabled.
Table 19-9. PWMCAE Field Descriptions
Note: Bits related to available channels have functional significance. Writing to unavailable bits has no effect. Read from
unavailable bits return a zero
Field Description
7–0
CAE[7:0]
Center Aligned Output Modes on Channels 7–0
0 Channels 7–0 operate in left aligned output mode.
1 Channels 7–0 operate in center aligned output mode.
Module Base + 0x0005
76543210
R
CON67 CON45 CON23 CON01 PSWAI PFRZ
00
W
Reset 0 0 0 00000
= Unimplemented or Reserved
Figure 19-8. PWM Control Register (PWMCTL)