MOTOROLA
Chapter 17. Modular Input/Output Subsystem (MIOS14)
17-43
MIOS14 Double Action Submodule (MDASM)
17.9.6.3 MDASM Data B (MDASMBR) Register
Table 17-19. MDASMAR Bit Descriptions
Bits
Name
Description
0:15
AR
MDASMAR is the data register associated with channel A; its use varies with the different modes of
operation:
DIS mode: MDASMAR can be accessed to prepare a value for a subsequent mode selection.
IPWM mode: MDASMAR contains the captured value corresponding to the trailing edge of the measured
pulse.
IPM and IC modes: MDASMAR contains the captured value corresponding to the most recently detected
dedicated edge (rising or falling edge).
OCB and OCAB modes: MDASMAR is loaded with the value corresponding to the leading edge of the
pulse to be generated. Writing to MDASMAR in the OCB and OCAB modes also enables the
corresponding channel A comparator until the next successful comparison.
OPWM mode: MDASMAR is loaded with the value corresponding to the leading edge of the PWM pulse
to be generated.
NOTE: In IC, IPM, or IPWM mode, when a read to register A or B occurs at the same time as a counter
bus capture into that register and the counter bus is changing value, then the counter bus capture to that
register is delayed.
MSB
01
23
45
67
89
10
11
12
13
14
LSB
15
Field
BR
SRESET
Undefined
Addr
0x30 605A, 0x30 6062, 0x30 606A, 0x30 6072, 0x30 607A,
0x30 60DA, 0x30 60E2, 0x30 60EA, 0x30 60F2, 0x30 60FA
Figure 17-23. MDASM DataB Register (MDASMBR)
Table 17-20. MDASMBR Bit Descriptions
Bits Name
Description
0:15
BR
MDASMBR is the data register associated with channel B; its use varies with the different modes of operation.
Writing to register B always writes to B1 and, depending on the mode selected, sometimes to B2. Reading
register B either reads B1 or B2 depending on the mode selected.
In the DIS mode, MDASMBR can be accessed to prepare a value for a subsequent mode selection. In this
mode, register B1 is accessed in order to prepare a value for the OPWM mode. Unused register B2 is hidden
and cannot be read, but is written with the same value when register B1 is written.
In the IPWM mode, MDASMBR contains the captured value corresponding to the leading edge of the
measured pulse. In this mode, register B2 is accessed; buffer register B1 is hidden and is not readable.
In the IPM and IC modes, MDASMBR contains the captured value corresponding to the previously dedicated
edge (rising or falling edge). In this mode, register B2 is accessed; buffer register B1 is hidden and is not
readable.
In the OCB and OCAB modes, MDASMBR is loaded with the value corresponding to the trailing edge of the
pulse to be generated. Writing to MDASMBR in the OCB and OCAB modes also enables the corresponding
channel B comparator until the next successful comparison. In this mode, register B2 is accessed; buffer
register B1 is hidden and is not readable.
In the OPWM mode, MDASMBR is loaded with the value corresponding to the trailing edge of the PWM pulse
to be generated. In this mode, register B1 is accessed; buffer register B2 is hidden and cannot be accessed.
NOTE: In IC, IPM, or IPWM mode, when a read to register A or B occurs at the same time as a counter bus
capture into that register and the counter bus is changing value, then the counter bus capture to that register
is delayed.