Toshiba TLCS-900/H1 Series Manual page 439

3.21 Boot ROM
A boot ROM is built-in to download user's boot program.
Three downloading methods are supported.
3.21.1 Operation Mode
There are 2 operation modes: MULTI mode and BOOT mode. Each mode is set according
to the status of the AM1 and AM0 pins when
(1) MULTI mode:
(2) BOOT mode:
Mode Setting Pins
RESET
Order of
Name
Setting
(a) 1
(b) 2
(c) 3
After reset, the CPU fetches and executes instructions from an
external memory.
After reset, the CPU fetches and executes instructions from
the internal boot ROM. A user program which executes
programming to on-board memory (e.g., NOR flash) is loaded
from either NAND flash, UART or USB to internal RAM, and
then branched to the internal RAM.
This operation will initiate a user program boot.
Table 3.21.2 shows an outline of boot operation.
Table 3.21.1 Operation
AM1 AM0
0 1
MULTI
1 0
Start from internal boot ROM)
1 1 BOOT (
TEST (Disabled to set)
0 0
Table 3.21.2 Outline
Source
NAND flash
PC
PC
92CH21-437
is asserted.
RESET
Mode
Operation Mode
Start from external 16-bit bus
memory
Start from external 32-bit bus
memory
of Boot Operation
Loading
I/F
Destination
Data bus
Internal RAM
UART
USB
TMP92CH21
Operation after
Loading
Branch to
internal RAM
2009-06-19