MC9S12G Datasheet, PDF (214/1160 Pages) Freescale Semiconductor, Inc – Ignores external trigger. Performs one conversion sequence and stops.

Port Integration Module (S12GPIMV0)
the ETRIG will be driven by the PWM internally. If the related PWM channel is not enabled, the ETRIG
function will be triggered by other functions on the pin including general-purpose input.
Table 2-95 illustrates the resulting trigger sources and their dependencies. Shaded fields apply to 20
TSSOP with shared ACMP analog input functions on port AD pins only.
Table 2-95. ETRIG Sources
ATDDIEN of ADC
&
ACDIEN of ACMP
PWM
Enable
Peripheral
Enable¹
0
0
0
0
0
1
0
1
0
0
1
1
1
0
0
1
0
1
1
1
0
1
1
1
1 _{With higher priority than PWM on pin}
ETRIG
Source
Comment
Const. 1
Const. 1
PWM
PWM
Pin
Pin
Pin
PWM
Forced High
Forced High
Internal Link
Internal Link
Driven by General-Purpose Function
Driven by Peripheral
Driven by PWM
Internal Link
2.6.5 Emulation of Smaller Packages
The Package Code Register (PKGCR) allows the emulation of smaller packages to support software
development and debugging without need to have the actual target package at hand. Cross-device
programming for the shared functions is also supported because smaller package sizes than the given
device is offered in can be selected¹.
The PKGCR can be written in normal mode once after reset to overwrite the factory pre-programmed
value, which determines the actual package. Further attempts are blocked to avoid inadvertent changes
(blocking released in special mode). Trying to select a package larger than the given device is offered in
will be ignored and result in the “illegal” code being written.
When a smaller package is selected the pin availability and pin functionality changes according to the
target package specification. The input buffers of unused pins are disabled however the output functions
of unused pins are not disabled. Therefore these pins should be don’t-cared.
Depending on the different feature sets of the G-family derivatives the input buffers of specific pins, which
are shared with analog functions need to be explicitly enabled before they can be used with digital input
functions. For example devices featuring an ACMP module contain a control register for the related input
buffers, which is not available on other family members. Also larger devices in general feature more ADC
channels with individual input buffer enable bits, which are not present on smaller ones. These differences
need to be accounted for when developing cross-functional code.
1. Except G128/G96 in 20 TSSOP: Internal routing of PWM to ETRIG is not available.
MC9S12G Family Reference Manual, Rev.1.01
214
Freescale Semiconductor
This document is valid for the S12G96 and the S12G128 device. All information related to other devices is preliminary.