SPRUHM9H October 2014 – May 2024 TMS320F28075 , TMS320F28075-Q1 , TMS320F28076
The Flash bank and pump consume a significant amount of power when active. The Flash module provides a mechanism to power-down the Flash bank and pump. Special timers automatically sequence the power-up of the Bank. The 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 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 the 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 the FPAC1 register). The application software can also check the current power mode of the Flash bank and charge pump by reading the FBPRDY register. See 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.
Before configuring Flash bank and pump power modes to sleep, make sure that the VREADST (refer to the FBAC register) value is 0xF (which is the reset value) to make sure the requisite delay is needed for the Flash pump/bank to come out of low-power mode later.
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)