Modular Input/Output Subsystem (MIOS14)
MPC561/MPC563 Reference Manual, Rev. 1.2
Freescale Semiconductor
17-43
17.9.6.4
MDASM Status/Control Register (MDASMSCRD) (Duplicated)
The MDASMSCRD and the MDASMSCR are the same registers accessed at two different addresses.
Reading or writing to one of these two addresses has exactly the same effect.
WARNING
The user should not write directly to the address of the MDASMSCRD. This
register’s address may be reserved for future use and should not be accessed
by the software to ensure future software compatibility.
The duplication of the SCR register allows coherent 32-bit accesses when using an RCPU.
17.9.6.5
MDASM Status/Control Register (MDASMSCR)
The status and control register gathers a read only bit reflecting the status of the MDASM signal as well
as read/write bits related to its control and configuration.
The signal input status bit reflects the status of the corresponding signal when in input mode. When in
output mode, the PIN bit only reflects the status of the output flip-flop.
Table 17-20. MDASMBR Bit Descriptions
Bits
Nam
e
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.
Summary of Contents for MPC561
Page 84: ...MPC561 MPC563 Reference Manual Rev 1 2 lxxxiv Freescale Semiconductor...
Page 144: ...Signal Descriptions MPC561 MPC563 Reference Manual Rev 1 2 2 46 Freescale Semiconductor...
Page 206: ...Central Processing Unit MPC561 MPC563 Reference Manual Rev 1 2 3 62 Freescale Semiconductor...
Page 302: ...Reset MPC561 MPC563 Reference Manual Rev 1 2 7 14 Freescale Semiconductor...
Page 854: ...Time Processor Unit 3 MPC561 MPC563 Reference Manual Rev 1 2 19 24 Freescale Semiconductor...
Page 968: ...Development Support MPC561 MPC563 Reference Manual Rev 1 2 23 54 Freescale Semiconductor...
Page 1144: ...Internal Memory Map MPC561 MPC563 Reference Manual Rev 1 2 B 34 Freescale Semiconductor...
Page 1212: ...TPU3 ROM Functions MPC561 MPC563 Reference Manual Rev 1 2 D 60 Freescale Semiconductor...
Page 1216: ...Memory Access Timing MPC561 MPC563 Reference Manual Rev 1 2 E 4 Freescale Semiconductor...