Set The Transmitter Pins To Operate As Mcbsp Pins; Enable/Disable The Digital Loopback Mode; Enable/Disable The Clock Stop Mode; Register Bit Used To Enable/Disable The Digital Loopback Mode - Texas Instruments Concerto F28M35 Series Technical Reference Manual

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transmit register. The DMA PERINTFLG is edge-sensitive and will fail to recognize the XRDY, which is
continuously high.
For more details about McBSP reset conditions and effects, see
a McBSP.

15.9.3 Set the Transmitter Pins to Operate as McBSP Pins

To configure a pin for its McBSP function , you should configure the bits of the GPxMUXn register
appropriately. In addition to this, bits 12 and 13 of the PCR register must be set to 0. These bits are
defined as reserved.

15.9.4 Enable/Disable the Digital Loopback Mode

The DLB bit determines whether the digital loopback mode is on. DLB is described in
Table 15-48. Register Bit Used to Enable/Disable the Digital Loopback Mode
Register Bit
SPCR1 15
15.9.4.1 Digital Loopback Mode
In the digital loopback mode, the receive signals are connected internally through multiplexers to the
corresponding transmit signals, as shown in
a single DSP device; the McBSP receives the data it transmits.
Table 15-49. Receive Signals Connected to Transmit Signals in Digital Loopback Mode
This Receive Signal
DR (receive data)
FSR (receive frame synchronization)
MCLKR (receive clock)

15.9.5 Enable/Disable the Clock Stop Mode

The CLKSTP bits determine whether the clock stop mode is on. CLKSTP is described in
Table 15-50. Register Bits Used to Enable/Disable the Clock Stop Mode
Register Bit
SPCR1 12-11
SPRUH22I – April 2012 – Revised November 2019
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Name Function
DLB Digital loopback mode
DLB = 0
DLB = 1
Table
Name Function
CLKSTP Clock stop mode
CLKSTP = 0Xb
CLKSTP = 10b
CLKSTP = 11b
Copyright © 2012–2019, Texas Instruments Incorporated
Section 15.10.2, Resetting and Initializing
Digital loopback mode is disabled.
Digital loopback mode is enabled.
15-49. This mode allows testing of serial port code with
Is Fed Internally by
This Transmit Signal
DX (transmit data)
FSX (transmit frame synchronization)
CLKX (transmit clock)
Clock stop mode disabled; normal clocking for
non-SPI mode.
Clock stop mode enabled without clock delay
Clock stop mode enabled with clock delay
C28 Multichannel Buffered Serial Port (McBSP)
Transmitter Configuration
Table 15-48.
Reset
Type Value
R/W 0
Table 15-50.
Reset
Type Value
R/W 00
1099