SPRSP45B March 2020 – December 2020 TMS320F280021 , TMS320F280021-Q1 , TMS320F280023 , TMS320F280023-Q1 , TMS320F280023C , TMS320F280025 , TMS320F280025-Q1 , TMS320F280025C , TMS320F280025C-Q1
PRODUCTION DATA
The following section summarizes the sampling window width for input signals for various input qualifier configurations.
Sampling frequency denotes how often a signal is sampled with respect to SYSCLK.
Sampling frequency = SYSCLK/(2 × QUALPRD), if QUALPRD ≠ 0
Sampling frequency = SYSCLK, if QUALPRD = 0
Sampling period = SYSCLK cycle × 2 × QUALPRD, if QUALPRD ≠ 0
In the previous equations, SYSCLK cycle indicates the time period of SYSCLK.
Sampling period = SYSCLK cycle, if QUALPRD = 0
In a given sampling window, either 3 or 6 samples of the input signal are taken to determine the validity of the signal. This is determined by the value written to GPxQSELn register.
Case 1:
Qualification using 3 samples
Sampling window width = (SYSCLK cycle × 2 × QUALPRD) × 2, if QUALPRD ≠ 0
Sampling window width = (SYSCLK cycle) × 2, if QUALPRD = 0
Case 2:
Qualification using 6 samples
Sampling window width = (SYSCLK cycle × 2 × QUALPRD) × 5, if QUALPRD ≠ 0
Sampling window width = (SYSCLK cycle) × 5, if QUALPRD = 0
Figure 7-23 shows the general-purpose input timing.