RH850 datasheet(16/66 Pages) RENESAS

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Data Flash Access Library - Type T01, European Release

Functional Specifications

R01US0079ED0103

User Manual

Details on the request variable structure and its members are given later in section 4.3.3

“r_fdl_request_t”. Please also note that not all structure members are required for all commands. The

individual command descriptions in section 4.5 “Commands” provide the corresponding detailed

information.

3.3 Background Operation

The flash technology provided by Renesas enables the application to write/erase the Data Flash in

parallel to the CPU execution. In order to satisfy the operation in concurrent or distributed systems, the

command execution is divided into two steps:

1. Initiation of the command execution using R_FDL_Execute

2. Processing of the requested command state by using R_FDL_Handler

This approach comes with one important advantage: Command processing can be done centrally at one

place in the target system (normally the idle-loop or the scheduler loop), while the status of the requests

can be polled locally within the requesting tasks.

Please note that R_FDL_Execute only initiates the command execution and returns immediately with the

request-status "busy" after execution of the first internal state (or an error in case the request cannot be

accepted).

The device flash hardware is responsible for executing the operation in the background. The device

hardware operation might be divided into multiple operations, each performed on a separate occasion,

depending on the number of blocks and data items. The first operation is conducted by calling the

R_FDL_Execute function. The second and subsequent operations are triggered by calling the

R_FDL_Handler function. Thus, there is a need to call the R_FDL_Handler function multiple times.

Processing is suspended from the time each separate operation is completed until the next one is

triggered. Therefore, as the time interval between R_FDL_Handler functions call increases, so does the

overall processing time.

An exception to this background operation is R_FDL_CMD_READ command that is executed

synchronously during R_FDL_Execute function.

Figure 4: Usage of the request structure

Application

bufAddr_u32

idx_u32

cnt_u16

accessType_enu

myRequest

status_enu

FDL

command_enu

RH850 Datasheet(PDF) 16 Page - Renesas Technology Corp