Registers
1175
SPRUH82C – April 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
Multichannel Audio Serial Port (McASP)
24.1.29 Transmit Clock Control Register (ACLKXCTL)
The transmit clock control register (ACLKXCTL) configures the transmit bit clock (ACLKX) and the transmit
clock generator. The ACLKXCTL is shown in
and described in
Figure 24-62. Transmit Clock Control Register (ACLKXCTL)
31
16
Reserved
(A)
R-0
15
8
7
6
5
4
0
Reserved
(A)
CLKXP
ASYNC
CLKXM
CLKXDIV
R-0
R/W-0
R/W-1
R/W-1
R/W-0
LEGEND: R/W = Read/Write; R = Read only; -
n
= value after reset
A If writing to this field, always write the default value for future device compatibility.
Table 24-37. Transmit Clock Control Register (ACLKXCTL) Field Descriptions
Bit
Field
Value
Description
31-8
Reserved
0
Reserved. The reserved bit location always returns the default value. A value written to this field has no
effect. If writing to this field, always write the default value for future device compatibility.
7
CLKXP
Transmit bitstream clock polarity select bit.
0
Rising edge. External receiver samples data on the falling edge of the serial clock, so the transmitter
must shift data out on the rising edge of the serial clock.
1
Falling edge. External receiver samples data on the rising edge of the serial clock, so the transmitter
must shift data out on the falling edge of the serial clock.
6
ASYNC
Transmit/receive operation asynchronous enable bit.
0
Synchronous. Transmit clock and frame sync provides the source for both the transmit and receive
sections. Note that in this mode, the receive bit clock is an inverted version of the transmit bit clock. See
for more details.
1
Asynchronous. Separate clock and frame sync used by transmit and receive sections.
5
CLKXM
Transmit bit clock source bit.
0
External transmit clock source from ACLKX pin.
1
Internal transmit clock source from output of programmable bit clock divider.
4-0
CLKXDIV
0-1Fh
Transmit bit clock divide ratio bits determine the divide-down ratio from AHCLKX to ACLKX.
0
Divide-by-1
1h
Divide-by-2
2h-1Fh
Divide-by-3 to divide-by-32