MC9S12G Datasheet, PDF (524/1160 Pages) Freescale Semiconductor, Inc – Ignores external trigger. Performs one conversion sequence and stops.

Freescale’s Scalable Controller Area Network (S12MSCANV3)
For microcontrollers without a clock and reset generator (CRG), CANCLK is driven from the crystal
oscillator (oscillator clock).
A programmable prescaler generates the time quanta (Tq) clock from CANCLK. A time quantum is the
atomic unit of time handled by the MSCAN.
Tq= ₍^{---P----r---e----s-f--c-C---aA----lN--e--C-r---L---v-K--a----l--u----e----}₎
Eqn. 16-2
A bit time is subdivided into three segments as described in the Bosch CAN 2.0A/B specification. (see
Figure 16-44):
• SYNC_SEG: This segment has a fixed length of one time quantum. Signal edges are expected to
happen within this section.
• Time Segment 1: This segment includes the PROP_SEG and the PHASE_SEG1 of the CAN
standard. It can be programmed by setting the parameter TSEG1 to consist of 4 to 16 time quanta.
• Time Segment 2: This segment represents the PHASE_SEG2 of the CAN standard. It can be
programmed by setting the TSEG2 parameter to be 2 to 8 time quanta long.
Bit Rate= ₍---n----u----m------b----e---r------o----f---f--T^T---^q-i--m-----e-------Q-----u----a----n----t--a----₎
Eqn. 16-3
NRZ Signal
SYNC_SEG
Time Segment 1
(PROP_SEG + PHASE_SEG1)
Time Segment 2
(PHASE_SEG2)
1
4 ... 16
8 ... 25 Time Quanta
= 1 Bit Time
2 ... 8
Transmit Point
Sample Point
(single or triple sampling)
Figure 16-44. Segments within the Bit Time
MC9S12G Family Reference Manual, Rev.1.01
524
Freescale Semiconductor
This document is valid for the S12G96 and the S12G128 device. All information related to other devices is preliminary.