AN4035 datasheet(37/42 Pages) STMICROELECTRONICS

37 / 42 page

AN4035

Creating the Flash programming tool

Doc ID 022669 Rev 2

37/41

6.2.2

FlashInit

After the drivers are loaded into internal SRAM, operations on the Flash can begin. The

FlashInit driver should be called first to initialize the Flash.

This function reads the Flash configuration information from the Flash control registers and

initialize parameters in SSD configuration structure. ‘FlashInit()’ must be called prior to any

other flash operations.

The steps required are outlined below.

Setup the SSD_CONFIG structure as required. This is documented in the SSD user’s

manual. The user should correctly initialize the fields c90flRegBase, mainArrayBase,

shadowRowBase, shadowRowSize, pageSize, and BDMEnable. The other fields are

initialized when FlashInit is executed. BDMEnable should be set to 1 to cause debug

mode to be entered via a software breakpoint when each driver completes execution.

This is the easiest way for the external tool to determine when driver execution is

complete.

Setup r1 as the stack pointer by writing r1 using the method described in Section 3.10:

GPR access.

Setup r3 to point to the SSD_CONFIG structure in internal SRAM.

Set the PC to the beginning of FlashInit minus 0x4 and load the IR with a nop

(0x60000000). See Section 3.7: CPU Status and Control Scan Chain Register

(CPUSCR) for details.

Exit debug mode and begin execution of the driver as described in Section 3.9: Exit

from debug mode to normal execution.

Poll the OnCE Status Register to determine when debug mode has been re-entered.

Reading the OnCE Status Register is described in Section 3.4: OnCE status register.

When debug mode has been entered, read the return value in r3.

6.2.3

SetLock

After the Flash has been initialized using the FlashInit function, the SetLock function should

be called as many times as required to unlock or lock the appropriate Flash blocks. This

function sets the block lock state for Shadow/Low/Middle/High address space on the C90FL

module to protect them from program/erase. The API provides password to enable block

lock register writes when needed and write the block lock value to block lock register for the

requested address space.

For the low and mid blocks as well as the shadow block, the lock bits in both the primary and

secondary lock registers must be set appropriately. It is recommended to lock the shadow

block unless programming of the shadow block is absolutely necessary. Erasing the shadow

block without re-programming the censorship information prior to a reset causes the device

to be censored with an invalid password and the Flash of the device is not able to be

uncensored.

The steps to call the SetLock driver are listed below.

AN4035 датащи(PDF) 37 Page - STMicroelectronics

AN4035 датащи(HTML) 37 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42

датащи скачать

ссылки URL