R01US0079ED0103 Datasheet, PDF (22/66 Pages) Renesas Technology Corp – RENESAS 32-Bit MCU

Data Flash Access Library - Type T01, European Release
Functional Specifications
3.6 Stand-by and Wake-up functionality
Entering a device power save (stand-by) mode is not allowed, when a Data Flash operation is on-going.
Due to that, especially Data Flash Erase operation can delay entering a power save mode significantly. In
order to allow fast entering of such mode, the functions R_FDL_StandBy and R_FDL_WakeUp have been
introduced. The main functionality of the functions is to suspend a possibly on-going Data Flash Erase or
Write operation (R_FDL_StandBy) and resume it after waking up from power save mode
(R_FDL_WakeUp).
Once started, stand-by processing must always end in stand-by status. Calling the R_FDL_StandBy
does not necessarily immediately suspend any Data Flash operation, as suspend might be delayed by the
device internal hardware or might not be supported at all (only Erase and Write are suspend-able). In this
case, the R_FDL_StandBy function must be called repeatedly until the stand-by status is reached.
Blank Check and Read Data Flash operations are suspendable from software point of view, but the library
will wait for the operation to be finished by hardware while suspend is processed and the result will be
presented after resuming. This wait however is not that important because blank check and read
operations are much faster than erase or write.
In case the FDL is in an idle state (no on-going Data Flash operations), by calling the R_FDL_StandBy
the FDL will immediately enter the Stand-By state. By calling the R_FDL_WakeUp, the FDL will return to
previous state (in this case the idle state).
The following pictures describe the library behaviour in case a stand-by request is issued during FDL
operation:
User
application
R_FDL_Execute (Erase 2 blocks)
R_FDL_BUSY
FDL
Start erase block
Data Flash
programming
hardware
R_FDL_Handler
R_FDL_BUSY
Check (Busy)
…………………………………………………………
Erase
First block
R_FDL_Handler
R_FDL_BUSY
Start erase block
R_FDL_Handler
R_FDL_BUSY
Check (Busy)
Erase
Second block
R_FDL_StandBy
R_FDL_OK
Suspend
…………………………………………………………
R_FDL_WakeUp
R_FDL_OK
Start erasing
interrupted block
Erase
second block
interrupted
StasntadtBey
R_FDL_Handler
R_FDL_BUSY
Check (Busy)
…………………………………………………………
Erase
Block 2
R_FDL_Handler
R_FDL_OK
Check (Ready)
Idle
Figure 10: Stand-By processing on a Data Flash Erase operation
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User Manual