Frame Phases
1049
SPRUH22I – April 2012 – Revised November 2019
Copyright © 2012–2019, Texas Instruments Incorporated
C28 Multichannel Buffered Serial Port (McBSP)
In the preceding timing diagram (
), a 1-bit data delay is selected.
5. The McBSP shifts data bits from the transmit shift register(s) to the DX pin.
When activity is not properly timed, errors can occur. See the following topics for more details:
•
Overwrite in the Transmitter
(
•
Underflow in the Transmitter
•
Unexpected Transmit Frame-Synchronization Pulse
15.3.7 Interrupts and DMA Events Generated by a McBSP
The McBSP sends notification of important events to the CPU and the DMA controller via the internal
signals shown in
.
Table 15-3. Interrupts and DMA Events Generated by a McBSP
Internal Signal
Description
RINT
Receive interrupt
The McBSP can send a receive interrupt request to CPU based upon a selected condition in the receiver of
the McBSP (a condition selected by the RINTM bits of SPCR1).
XINT
Transmit interrupt
The McBSP can send a transmit interrupt request to CPU based upon a selected condition in the transmitter
of the McBSP (a condition selected by the XINTM bits of SPCR2).
REVT
Receive synchronization event
An REVT signal is sent to the DMA when data has been received in the data receive registers (DRRs).
XEVT
Transmit synchronization event
An XEVT signal is sent to the DMA when the data transmit registers (DXRs) are ready to accept the next
serial word for transmission.
15.4 McBSP Sample Rate Generator
Each McBSP contains a sample rate generator (SRG) that can be programmed to generate an internal
data clock (CLKG) and an internal frame-synchronization signal (FSG). CLKG can be used for bit shifting
on the data receive (DR) pin and/or the data transmit (DX) pin. FSG can be used to initiate frame transfers
on DR and/or DX.
is a conceptual block diagram of the sample rate generator.