SPRUHX5I August 2014 – May 2024 TMS320F28374S , TMS320F28375S , TMS320F28375S-Q1 , TMS320F28376S , TMS320F28377S , TMS320F28377S-Q1 , TMS320F28378S , TMS320F28379S
The Flash bank and pump consume a significant amount of power when active. The Flash module provides a mechanism to power-down Flash banks and pump. Special timers automatically sequence the power-up of Bank0 and Bank1 independently of each other. The shared charge pump module has an independent power-up timer as well.
The Flash bank and OTP memory operate in three power modes: Sleep (lowest power), Standby, and Active (highest power)
The charge pump operates in two power modes:
Any access to any Flash bank/OTP memory causes the charge pump to go into active mode, if the charge pump is in sleep mode. An erase or program command causes the charge pump and bank to become active. If any bank is in active or in standby mode, the charge pump is in active mode, independent of the pump power mode control configuration (PMPPWR bit-field in FPAC1 register).
To power down the Flash pump, the CPU must power down the Flash pump using the following sequence without any Flash accesses in between. The Flash pump does not enter low-power mode if the following sequence is not followed.
The previous procedure must be executed from RAM and not from Flash. Note that exclusive control of the Flash pump must be assigned to a FMC (using PUMPREQUEST, Flash pump ownership control register) before configuring the PMPPWR bit field of the FPAC1 register as shown in the previous sequence. As the charge pump is shared between FMC0 and FMC1, the effective PMPPWR value used when powering down the pump is of the FMC (out of FMC0 and FMC1) that owns the pump. The application software can check the current power mode of Flash bank by reading the FBPRDY register. The PUMPRDY bit can be used by the application software to identify the current power mode status of the pump. A value of 0 in the PUMPRDY bit in both FMC0 and FMC1 indicates that the charge pump is in sleep mode. A value of 1 in PUMPRDY bit in either FMC0 or FMC1 or in both FMC0 and FMC1 indicates that the charge pump is in active mode. Refer to the register descriptions, Section 3.17, for detailed information.
While the pump is in sleep state, a charge pump sleep down counter holds a user configurable value (PSLEEP bit field in the FPAC1 register) and when the charge pump exits sleep power mode, the down counter delays from 0 to PSLEEP prescaled SYSCLK clock cycles (prescaled clock is SYSCLK/2) before putting the charge pump into active power mode. Note that the configured PSLEEP value must yield at least a delay of 20 µs for the pump to go to active mode. Refer to the register descriptions, Section 3.17, for detailed information
Following are the number of cycles for the Bank and pump to wake up from low-power modes:
Where in Flash clock = SYSCLK/(RWAIT+1)