MC68F375
CONFIGURABLE TIMER MODULE (CTM9)
MOTOROLA
REFERENCE MANUAL
Rev. 25 June 03
13-23
13.4.4.4 SDATB — SASM Data Register B
SDATB is the 16-bit read-write register associated with channel A. In the IC mode,
SDATB contains the last captured value. In the OC, OCT and OP modes, it is loaded
with the value of the next output compare. SDATB is not affected by reset.
13.5 Double-Action Submodule (DASM)
The double-action submodule (DASM) provides two 16-bit input captures or two 16-bit
output compare functions that can occur automatically without software intervention.
The input edge detector is programmable to cause the capture function to occur on the
desired edges. The output flip-flop is set by one of the output compares and is reset
by the other one. In either the input capture modes or the output compare modes, an
optional interrupt is available to the software. Software selection is provided for which
of two incoming time-base buses is used for input captures or output compares.
The DASM can work in six different modes: disable mode, pulse length measurement,
period measurement, input capture mode, single pulse generation, and continuous
pulse width generation.
The DASM has three data registers that are accessible to the software from the vari-
ous modes. For some of the modes, two of the registers are cascaded together to
provide double buffering. The value in one register is transferred to another register
automatically at the correct time so that the minimum pulse (measurement or genera-
tion) is just one time-base bus count. See Figure 13-6 for a DASM block diagram.
S14ICB — SASM Status/Interrupt Control Register B
0xYF F274
S16ICB
0xYF F284
S18ICB
0xYF F294
S20ICB
0xYF F2A4
MSB
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
LSB
0
FLAG
0
BSL
IN
0
FORCE
EDOUT
00
MOD
E1
MOD
E0
RESET:
0
S14DATB — SASM Data Register B
0xYF F276
S16DATB
0xYF F286
S18DATB
0xYF F296
S20DATB
0xYF F2A6
MSB
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
LSB
0
MSB
LSB
RESET:
U
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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