Texas Instruments TMS320C6201 Reference Manual page 395

Table 11–20. Receive/Transmit Channel Enable Register Field Description
Name Function
RCEA n
Receive channel enable
0 n 15
RCEA n = 0: Disables reception of the n th element in an even-numbered subframe in partition A
RCEA n = 1: Enables reception of the n th element in an even-numbered subframe in partition A
XCEA n Transmit channel enable
0 n 15
XCEA n = 0: Disables transmission of the n th element in an even-numbered subframe in
partition A
XCEA n = 1: Enables transmission of the n th element in an even-numbered subframe in
partition A
RCEB n Receive channel enable
0 n 15
(R/X)CEB n = 0: Disables reception of the n th element in an odd-numbered subframe in partition B
(R/X)CEB n = 1: Enables reception of the n th element in an odd-numbered subframe in partition B
XCEB n Transmit channel enable
0 n 15
XCEB n = 0: Disables transmission of the n th element in anodd-numbered subframe in partition B
XCEB n = 1: Enables transmission of the n th element in an odd-numbered subframe in partition B
11.6.3.2 Changing Element Selection
Using the multichannel selection feature, a static group of 32 elements can be
enabled and remains enabled with no CPU intervention until this allocation is
modified. An arbitrary number of, group of, or all of the elements within a frame
can be accessed by updating the block allocation registers during the course of
the frame in response to the end-of-subframe interrupts (see section 11.6.3.3
for information about these interrupts).
Note:
You must be careful not to affect the currently selected subframe when chang-
ing the selection.
The currently selected subframe is readable through the RCBLK and XCBLK
fields in the MCR for receive and transmit, respectively. The associated channel
enable register cannot be modified if it is selected by the appropriate
(R/X)P(A/B)BLK register to point toward the current subframe. Similarly, the
(R/X)PABLK and (R/X)PBBLK fields in the MCR cannot be modified while point-
ing to or being changed to point to the currently selected subframe. If the total
number of elements is 16 or less, the current partition is always pointed to. In
this case, only a reset of the serial port can change the element enabling.
Multichannel Selection Operation
Multichannel Buffered Serial Ports 11-77