10.1.3 SPI Signal Routing
The DLPC2607 device is designed to support two SPI slave devices, specifically, a serial flash and the PMD1000. Given this requires routing associated SPI signals to two locations while attempting to operate at 33.3 MHz, ensure that reflections do not compromise signal integrity. TI recommends the following:
- Split the SPICLK PCB signal trace from the DLPC2607 source to each slave device into separate routes as close to the DLPC2607 device as possible. Make the SPICLK trace length to each device equal in total length.
- Split the SPIDOUT PCB signal trace from the DLPC2607 source to each slave device into separate routes as close to the DLPC2607 device as possible. Make the SPIDOUT trace length to each device equal in total length (that is, use the same strategy as SPICLK).
- Make the SPIDIN PCB signal trace from each slave device to the point where they intersect on the return to the DLPC2607 device equal in length and as short as possible. Make sure they share a common trace back to the DLPC2607 device.
- SPICSZ0 and SPICSZ1 do not require special treatment because they are dedicated signals which drive only one device.