S9S12G48F1CLC Datasheet, PDF (662/1292 Pages) Freescale Semiconductor, Inc – Microcontrollers

Pulse-Width Modulator (S12PWM8B8CV2)
In concatenated mode, writes to the 16-bit counter by using a 16-bit access or writes to either the low or
high order byte of the counter will reset the 16-bit counter. Reads of the 16-bit counter must be made by
16-bit access to maintain data coherency.
Either left aligned or center aligned output mode can be used in concatenated mode and is controlled by
the low order CAEx bit. The high order CAEx bit has no effect.
Table 19-13 is used to summarize which channels are used to set the various control bits when in 16-bit
mode.
Table 19-13. 16-bit Concatenation Mode Summary
Note: Bits related to available channels have functional significance.
CONxx
CON67
CON45
CON23
CON01
PWMEx
PWME7
PWME5
PWME3
PWME1
PPOLx
PPOL7
PPOL5
PPOL3
PPOL1
PCLKx
PCLK7
PCLK5
PCLK3
PCLK1
CAEx
CAE7
CAE5
CAE3
CAE1
PWMx
Output
PWM7
PWM5
PWM3
PWM1
19.4.2.8 PWM Boundary Cases
Table 19-14 summarizes the boundary conditions for the PWM regardless of the output mode (left aligned
or center aligned) and 8-bit (normal) or 16-bit (concatenation).
Table 19-14. PWM Boundary Cases
PWMDTYx
PWMPERx
$00
(indicates no duty)
>$00
$00
(indicates no duty)
XX
XX
>$00
$00¹
(indicates no period)
$00¹
(indicates no period)
>= PWMPERx
XX
>= PWMPERx
XX
1 _{Counter = $00 and does not count.}
PPOLx
1
0
1
0
1
0
PWMx Output
Always low
Always high
Always high
Always low
Always high
Always low
19.5 Resets
The reset state of each individual bit is listed within the Section 19.3.2, “Register Descriptions” which
details the registers and their bit-fields. All special functions or modes which are initialized during or just
following reset are described within this section.
• The 8-bit up/down counter is configured as an up counter out of reset.
• All the channels are disabled and all the counters do not count.
MC9S12G Family Reference Manual, Rev.1.23
664
Freescale Semiconductor