SPRUIX1B October 2022 – April 2024 TMS320F2800132 , TMS320F2800133 , TMS320F2800135 , TMS320F2800137
Memory-mapped registers in the System Control operate on INTOSC1 clock domain; hence, any CPU writes to these registers requires a delay between subsequent writes otherwise a second write can be lost. The application needs to take this into consideration and add a delay in terms of the number of NOP instructions after every write to these registers that are mentioned in Table 3-18. The formula to compute delay between subsequent writes:
Delay (in SYSCLK cycles) = 3 × (FSYSCLK ÷ FINTOSC1) + 9
For Example - For SYSCLK = 100MHz
Delay (in SYSCLK cycles) = 3 × (100MHz ÷ 10MHz) + 9 = 39 SYSCLK cycles
| Registers requiring delay after every write |
|---|
| CLBCLKCTL |
| PERCLKDIVSEL |
| SYSCLKDIVSEL |
| SYSPLLCTL1 |
| SYSPLLMULT |
| WDCR |
| XCLKOUTDIVSEL |
| XTALCR |
| CLKSRCCTL1 |
| CLKSRCCTL2 |
| CLKSRCCTL3 |
| CPU1TMR2CTL (TMR2CLKCTL) |