SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
Two MIPI D-PHY compliant PHY receivers (CSI2_PHY1 and CSI2_PHY2, or generally referenced to as CSI2 PHY) immediately before the CAL module act as a physical connection and configuration of clock/data lanes with external sensors. A CSI2 PHY supports up to four configurations, depending on the required number of D-PHY data lane external sensors. The receivers are compatible with the MIPI D-PHY Specification v1.00.00. The selection of a CSI2 PHY in D-PHY mode must be done before reset and not on the fly.
The CSI2 PHY is controlled and must be configured first from the device Control Module for pad configuration. The differential data/clock lanes coming into the CSI2 PHY1 and CSI2 PHY2 are configured from registers explained in Section 10.4.5.3, CSI2 PHY Link Initialization Sequence.
There are two CSI2 PHY instances integrated in the device. As shown in Figure 10-5, the CSI2_PHY1 contains four data lanes and CSI2_PHY2 has two data lanes. Figure 10-5 shows the two CSI2 PHY cases, with their signals further covered in Section 10.4.6.2.1, CSI2 Physical Layer.
LANE 4 of CSI2_PHY1 can be used only as a data lane, never as a clock lane. All other configurations are possible.
CSI2_PHY1 and CSI2_PHY2 represent the overall PHY solution for connecting external sensors to feed the CAL module. The MIPI D-PHY function can support up to four data lane modules and one clock lane module. Reverse direction escape mode is not supported. The lane module polarity and positions are configurable; that is, any lane module can be chosen as the clock lane module (except otherwise notified), and the DX/DY data pad for each lane module can be configured as DP or DN pins defined. The configuration and the selection of D-PHY mode, data/clock are done through the device Control Module (see Control Module). The only exception is the four-data-lane use case, in which one corner lane is allowed to be only a data lane. Both CSI2 PHY modules can be configured through serial configuration protocol (SCP) interface.