SPRUHM9H October 2014 – May 2024 TMS320F28075 , TMS320F28075-Q1 , TMS320F28076
The XMCM bits of XCR2 determine whether all channels or only selected channels are enabled and unmasked for transmission. More details on enabling and masking are in Section 20.6.7.1. The McBSP has three transmit multichannel selection modes (XMCM = 01b, XMCM = 10b, and XMCM = 11b), which are described in Table 20-13.
XMCM | Transmit Multichannel Selection Mode |
---|---|
00b | No transmit multichannel selection mode is on. All channels are enabled and unmasked. No channels can be disabled or masked. |
01b | All channels are disabled unless the channels are selected in the appropriate transmit channel enable registers (XCERs). If enabled, a channel in this mode is also unmasked. |
The XMCME bit of MCR2 determines whether 32 channels or 128 channels are selectable in XCERs. | |
10b | All channels are enabled, but the channels are masked unless the channels are selected in the appropriate transmit channel enable registers (XCERs). |
The XMCME bit of MCR2 determines whether 32 channels or 128 channels are selectable in XCERs. | |
11b | This mode is used for symmetric transmission and reception. |
All channels are disabled for transmission unless the channels are enabled for reception in the appropriate receive channel enable registers (RCERs). Once enabled, the channels are masked unless the channels are also selected in the appropriate transmit channel enable registers (XCERs). | |
The XMCME bit of MCR2 determines whether 32 channels or 128 channels are selectable in RCERs and XCERs. |
As an example of how the McBSP behaves in a transmit multichannel selection mode, suppose that XMCM = 01b (all channels disabled unless individually enabled) and that you have enabled only channels 0, 15, and 39. Suppose also that the frame length is 40. The McBSP: