TMP92FD54AI datasheet(16/84 Pages) TOSHIBA

16 / 84 page

2006-01-27

92FD54AI-16

TMP92FD54AI

4.3

On-Board Programming Mode (User-Boot and Single-Boot)

On-board Programming Mode allows flash memory to be rewritten while it is mounted

on the user’s target system board. There are two versions of this mode: Single Boot

Mode, which supports the Toshiba proprietary method of rewriting via serial I/O, and

User Boot Mode (in Single-Chip mode), which allows user-defined rewriting methods to

be defined in Single-Chip Mode.

4.3.1

User Boot Mode (in Single-Chip Mode)

User Boot Mode enables a user-defined flash memory rewrite routine to be used. This

mode is used when the data transfer bus which the user application flash memory

rewrite program uses is not serial. Rewriting is performed in Single-Chip Mode. For

this reason the operation mode within Single-Chip Mode must be changed, from

Normal Mode (the mode in which the user application program normally operates) to

User Boot Mode, in which mode the flash memory can be rewritten. This requires that

a condition-judging program be incorporated into the user application reset-processing

program.

Any mode-switching condition may be set using the device’s I/Os as long as it is

suitable for the user system. Also, the user’s exclusive flash memory rewrite routine,

for use in User Boot Mode, may be programmed into the user application in advance, so

that it can be used to rewrite the flash memory after the device has entered User Boot

Mode. Furthermore, since the processor cannot read data from the internal flash

memory during an erase/program operation, the rewrite routine must be stored

somewhere outside the flash memory so that it can be executed. While the on-chip

flash memory is being rewritten in User Boot mode, all interrupts including the

non-maskable interrupt must be disabled.

The pages which follow explain the procedure for rewriting the flash memory using two

example case studies. In one case the rewrite routine is put into the internal flash

memory (1-A); in the other the rewrite routine is transferred from an external source

(1-B). For details of how to program/erase the flash memory, refer to Section 4.4,

Programming/Erasing Flash Memory during on-Board Programming.

TMP92FD54AI 数据表(PDF) 16 Page - Toshiba Semiconductor