Modulo Timer (MTIM)
MCF51CN128 Reference Manual, Rev. 6
18-4
Freescale Semiconductor
The TCLK input must be synchronized by the bus clock. Also, variations in duty cycle and clock jitter
must be accommodated. Therefore, the TCLK signal must be limited to one-fourth of the bus frequency.
The TCLK pin can be muxed with a general-purpose port pin. See
Chapter 2, “Pins and Connections
the pin location and priority of this function.
18.3
Register Definition
is a summary of MTIM registers.
Each MTIM includes four registers:
•
An 8-bit status and control register
•
An 8-bit clock configuration register
•
An 8-bit counter register
•
An 8-bit modulo register
Refer to the direct-page register summary in
” for the absolute address assignments
for all MTIM registers. This section refers to registers and control bits only by their names and relative
address offsets.
Some MCUs may have more than one MTIM, so register names include placeholder characters to identify
which MTIM is being referenced.
Table 18-1. External Signal Description
Signal
Function
I/O
TCLK
External clock source input into MTIM
I
Name
7
6
5
4
3
2
1
0
MTIMSC
R
TOF
TOIE
0
TSTP
0
0
0
0
W
TRST
MTIMCLK
R
0
0
CLKS
PS
W
MTIMCNT
R
COUNT
W
MTIMMOD
R
MOD
W
Figure 18-2. MTIM Register Summary