PLL0_SYSCLK2
PLL1_SYSCLK2
0
1
McASP0
CFGCHIP3[ASYNC3_CLKSRC]
Module
Clock
LPSC
PLL0_AUXCLK
TX/RX
Reference
Clock
Clock
Generator
ACLKX
AHCLKX
AHCLKR
ACLKR
On Chip
Frame Sync
Generator
AFSX
AFSR
Peripheral Clocking
128
SPRUH82C – April 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
Device Clocking
6.3.6 McASP Clocking
As shown in
, the McASP peripheral requires multiple clock sources. Internally, the module
clock is selected to be either PLL0_SYSCLK2 or PLL1_SYSCLK2 by configuring the ASYNC3_CLKSRC
bit in the chip configuration 3 register (CFGCHIP3) of the System Configuration Module.
The transmit and receive clocks are sourced internally or externally by configuring the McASP clock
control registers ACLKRCTL, AHCLKRCTL, ACLKXCTL, and AHCLKXCTL. If an external clock is driven
into a high-frequency master clock (AHCLKX or AHCLKR), the McASP module allows for a mixed clock
mode where the associated lower frequency clock (ACLKX or ACLKR) can be derived from the high-
frequency master clock through a programmable divider.
When the internal clock source option is selected, the transmit and receive clocks are derived from the
PLL0_AUXCLK clock through programmable dividers.
Figure 6-7. McASP Clocking Diagram