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Registers
1181
SPRUH82C – April 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
Multichannel Audio Serial Port (McASP)
24.1.35 Transmit Clock Check Control Register (XCLKCHK)
The transmit clock check control register (XCLKCHK) configures the transmit clock failure detection circuit.
The XCLKCHK is shown in
and described in
.
Figure 24-68. Transmit Clock Check Control Register (XCLKCHK)
31
24
23
16
XCNT
XMAX
R-0
R/W-0
15
8
7
4
3
0
XMIN
Reserved
(A)
XPS
R/W-0
R-0
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 24-43. Transmit Clock Check Control Register (XCLKCHK) Field Descriptions
Bit
Field
Value
Description
31-24
XCNT
0
Transmit clock count value (from previous measurement). The clock circuit continually counts the
number of CPU system clocks for every 32 transmit high-frequency master clock (AHCLKX) signals,
and stores the count in XCNT until the next measurement is taken.
23-16
XMAX
0-FFh
Transmit clock maximum boundary. This 8-bit unsigned value sets the maximum allowed boundary for
the clock check counter after 32 transmit high-frequency master clock (AHCLKX) signals have been
received. If the current counter value is greater than XMAX after counting 32 AHCLKX signals,
XCKFAIL in XSTAT is set. The comparison is performed using unsigned arithmetic.
15-8
XMIN
0-FFh
Transmit clock minimum boundary. This 8-bit unsigned value sets the minimum allowed boundary for
the clock check counter after 32 transmit high-frequency master clock (AHCLKX) signals have been
received. If XCNT is less than XMIN after counting 32 AHCLKX signals, XCKFAIL in XSTAT is set. The
comparison is performed using unsigned arithmetic.
7-4
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.
3-0
XPS
0-Fh
Transmit clock check prescaler value.
0
McASP system clock divided by 1
1h
McASP system clock divided by 2
2h
McASP system clock divided by 4
3h
McASP system clock divided by 8
4h
McASP system clock divided by 16
5h
McASP system clock divided by 32
6h
McASP system clock divided by 64
7h
McASP system clock divided by 128
8h
McASP system clock divided by 256
9h-Fh
Reserved