ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
Write of DXR
(D)
DXR to XSR copy
(C)
Write of DXR
(C)
XRDY
DX
FSX
C5
C6
C7
B0
B2
B3
B4
B5
B6
B7
A0
A1
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
B1
CLKX
DXR to XSR copy
(B)
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
Read of DRR
(B)
RBR-to-DRR copy
(B)
Read of DRR
(A)
RBR-to-DRR copy
(A)
RRDY
DR
FSR
C5
C6
C7
B0
B2
B3
B4
B5
B6
B7
A0
A1
B1
CLKR
Architecture
1211
SPRUH82C – April 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
Multichannel Buffered Serial Port (McBSP)
25.2.7.1 Receive Operation
shows serial reception. Once the receive frame synchronization signal (FSR) transitions to its
active state, it is detected on the first falling edge of the receivers CLKR. The data on the DR pin is then
shifted into the receive shift register (RSR) after the appropriate data delay as set by the RDATDLY bit in
the receive control register (RCR). The contents of RSR is copied to RBR at the end of every element on
the rising edge of the clock, provided RBR is not full with the previous data. Then, an RBR-to-DRR copy
activates the RRDY status bit in the serial port control register (SPCR) to 1 on the following falling edge of
CLKR. This indicates that the receive data register (DRR) is ready with the data to be read by the CPU or
the EDMA controller. RRDY is deactivated when the DRR is read by the CPU or the EDMA controller. See
also
and
.
Figure 25-16. Receive Operation
25.2.7.2 Transmit Operation
Once transmit frame synchronization occurs, the value in the transmit shift register (XSR) is shifted out
and driven on the DX pin after the appropriate data delay as set by the XDATDLY bit in the transmit
control register (XCR). The XRDY bit in the serial port control register (SPCR) is activated after every
DXR-to-XSR copy on the following falling edge of CLKX, indicating that the data transmit register (DXR)
can be written with the next data to be transmitted. XRDY is deactivated when the DXR is written by the
CPU or the EDMA controller.
illustrates serial transmission. See
for
information on transmit operation when the transmitter is pulled out of reset (XRST = 1). See also
and
.
Figure 25-17. Transmit Operation