TMP1942FDU Datasheet, PDF (28/106 Pages) Toshiba Semiconductor – 32bit TX System RISC

TMP1942FD
(1-B) Method 2: Transferring a Programming Routine from an External Host
(1) Determine the conditions (e.g., pin states) required for the flash memory to enter User Boot
mode and the I/O bus to be used to transfer new program code. Create hardware and software
accordingly. Before installing the TMP1942FD on a printed circuit board, write the following
program routines into an arbitrary flash block using programming equipment.
• Mode judgment routine: Code to determine whether or not to switch to User Boot mode
• Transfer routine:
Code to download new program code from a host controller
Also, prepare a programming routine on the host controller
• Programming routine: Code to download new program code from an external host
controller and re-program the flash memory
TMP1942FD
Flash Memory
Old Application
Program Code
[Reset Procedure]
(a) Mode Judgment Routine
(b)Transfer Routine
Host Controller
New Application
Program Code
I/O
(c) Programming Routine
RAM
(2) After RESET is released, the reset procedure determines whether to put the TMP1942FD
flash memory in User Boot mode. If mode switching conditions are met, the flash memory
enters User Boot mode. (All interrupts including NMI must be globally disabled while in
User Boot mode.)
TMP1942FD
Flash Memory
Old Application
Program Code
[Reset Procedure]
(a) Mode Judgment Routine
(b) Transfer Routine
Host Controller
New Application
Program Code
I/O
(c) Programming Routine
0 → 1 RESET
RAM
Conditions for
entering User Boot
mode (defined by
the user)
TMP1942FD-27