For applications that use a system host to program the initial configuration through I2C or SPI after power up, this general procedure can be followed:
- Apply power to the device to start in I2C or SPI mode (see Device Start-Up).
- Set all outputs to static low to verify that
there are no glitches at startup.
- For all outputs, configure the
OUT_x_CONFIGURATION registers.
- For only OUT0 and OUT1, configure
the OUT_x_CONFIGURATION and the OUT_x_STATIC_LOW registers.
- Write to all of the registers EXCEPT the following registers:
- The registers listed in Step 2.
- R25[0] (SYNC_EN)
- R21[6] (SYNC_SW)
- R23[6] (SWRST)
- R23[5:3] (DPLLx_SWRST)
- R23[2:0] (APLLx_SWRST)
- Perform global, DPLL, and APLL software resets by writing:
- SWRST = 1
- APLLx_SWRST = 1
- DPLLx_SWRST = 1
- SWRST = 0
- Note: The DPLLx_SWRST and APLLx_SWRST are self-clearing bits.
- Wait for the APLL or APLLs to lock by polling the
PLL loss of lock status registers, LOL_PLLx, before asserting SYNC_EN and SYNC_SW.
- Assert SYNC by writing:
- SYNC_EN = 1
- SYNC_SW = 1
- Modify the output registers listed in Step 2: change from static low to the desired output states.
- Dessert SYNC by writing:
- SYNC_SW = 0
- SYNC_EN = 0 (optional and not required)
- Optional, but recommended: Clear the interrupt (INTR) status flags. These bits are not self-clearing (sticky) and can get set during start-up while the DPLL and APLL registers are not yet properly configured.
Alternatively, use the part-specific TICS Pro profile to export a customized register programming sequence for the currently loaded .tcs file as shown in Figure 8-47.