SPRUHX5I August 2014 – May 2024 TMS320F28374S , TMS320F28375S , TMS320F28375S-Q1 , TMS320F28376S , TMS320F28377S , TMS320F28377S-Q1 , TMS320F28378S , TMS320F28379S
Table 20-41 shows how you can select various sources to provide the receive clock signal and affect the MCLKR pin. The polarity of the signal on the MCLKR pin is determined by the CLKRP bit.
In the digital loopback mode (DLB = 1), the transmit clock signal is used as the receive clock signal.
Also, in the clock stop mode, the internal receive clock signal (MCLKR) and the internal receive frame-synchronization signal (FSR) are internally connected to their transmit counterparts, CLKX and FSX.
DLB in SPCR1 | CLKRM in PCR | Source of Receive Clock | MCLKR Pin Status |
---|---|---|---|
0 | 0 | The MCLKR pin is an input driven by an external clock. The external clock signal is inverted as determined by CLKRP before being used. | Input |
0 | 1 | The sample rate generator clock (CLKG) drives internal MCLKR. | Output. CLKG, inverted as determined by CLKRP, is driven out on the MCLKR pin. |
1 | 0 | Internal CLKX drives internal MCLKR. To configure CLKX, see Section 20.9.19. | High impedance |
1 | 1 | Internal CLKX drives internal MCLKR. To configure CLKX, see Section 20.9.19. | Output. Internal MCLKR (same as internal CLKX) is inverted as determined by CLKRP before being driven out on the MCLKR pin. |