Active
state
state
Standby
state
Sleep
Delay
FACTIVEWAIT
cycles
Delay
FSTDBYWAIT
cycles
FSTDBYWAIT
cycles
FACTIVEWAIT
Delay
cycles
Delay
Highest
power
Lowest power
Longest
Wake up time
PWR=0,1
PWR=0,0
PWR=0,0
PWR=1,1
or access to
the Flash/OTP
PWR=0,1
PWR=1,1
or access to
the Flash/OTP
Reset
Figure 1-1. Flash Power Mode State Diagram
The duration of the delay is determined by the FSTDBYWAIT and FACTIVEWAIT registers. Moving from
the sleep state to a standby state is delayed by a count determined by the FSTDBYWAIT register. Moving
from the standby state to the active state is delayed by a count determined by the FACTIVEWAIT register.
Moving from the sleep mode (lowest power) to the active mode (highest power) is delayed by FSTD
FACTIVEWAIT. These registers should be left in their default state.
1.1.3.1 Flash and OTP Performance
CPU read or data fetch operations to the flash/OTP can take one of the following forms:
• 32-bit instruction fetch
• 16-bit or 32-bit data space read
• 16-bit program space read
Once flash is in the active power state, then a read or fetch access to the bank memory map area can be
classified as a flash access or an OTP access.
The main flash array is organized into rows and columns. The rows contain 2048 bits of information. Accesses to
flash and OTP are one of three types:
1.
Flash Memory Random Access
The first access to a 2048 bit row is considered a random access.
2.
Flash Memory Paged Access
While the first access to a row is considered a random access, subsequent accesses within the same row
are termed paged accesses.
The number of wait states for both a random and a paged access can be configured by programming the
FBANKWAIT register. The number of wait states used by a random access is controlled by the RANDWAIT
bits and the number of wait states used by a paged access is controlled by the PAGEWAIT bits. The
System Control and Interrupts
42
TMS320x2806x Microcontrollers
SPRUH18I – JANUARY 2011 – REVISED JUNE 2022
Copyright © 2022 Texas Instruments Incorporated
Содержание TMS320 2806 Series
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