MCF548x Reference Manual, Rev. 3
25-2 Freescale Semiconductor

Figure 25-2. Fixed Timer Channel Conceptual Block Diagram

Figure 25-3. Variable Timer Channel Conceptual Block Diagram

25.1.2 Overview

The CTM module provides two functions for the communications complex. First, it can be configured to

run as a baud clock generator for the communications channels. Second, it can be used as a task initiator

for the DMA. There are three main functional blocks within the CTM that accomplish these functions: the

slave bus interface, the fixed timer channel, and the variable timer channel.

The slave bus interface to the CTM processes tasks such as the address decode, clock synchronization,

clock pre-scaling, and read/write enable decode.

mode 15-bit Percent
(High Time)
cAcknowledge
clk
Miscellaneous Block
Counter timerInterrup
t
cInitiator
Comparators
source[3:0]
percent[1:0]
counterReference[15:0]
TCRselect
dataRd[23:0]
Register
Percent
16-bit Period
Counter
Internal Bus
mode
externalClkIn
cAcknowledge
clk
Miscellaneous Block
cInitiatorComparator
source
percent[1:0]
counterReference[23:0]
TCRselect
dataRd[23:0]
Register Percent 24-bit Percent
Counter
Internal Bus