SPRUIN7C March 2020 – March 2024 TMS320F280021 , TMS320F280021-Q1 , TMS320F280023 , TMS320F280023-Q1 , TMS320F280023C , TMS320F280025 , TMS320F280025-Q1 , TMS320F280025C , TMS320F280025C-Q1
The receiver module has a programmable delay line on each of the external signal inputs: RXCLK, RXD0, and RXD1. The delay elements introduce delays on the respective lines. This is to facilitate adjustment for signal delays introduced by system level components such as signal buffers, ferrite beads, isolators, and so on, or board delays such as uneven trace lengths, long cable length, and so on. The length of the delay is controlled by setting the RX_DLY_LINE_CTRL register values for each line. By default, no delay is introduced by the delay line elements. The delay values must only be adjusted while the FSIRX is held in soft reset, making sure that there are no active transmissions during this process. Figure 22-7 shows a representation of the delay line circuitry for the input signals. The implementation for RXCLK, RXD0, and RXD1 are replicas of this diagram. All circuits behave similarly.
For more information on skew compensation, refer to Fast Serial Interface (FSI) Skew Compensation.