T89C51RD2 ATMEL Corporation, T89C51RD2 Datasheet - Page 57

• Manufacturer Part Number: T89C51RD2
• Description: 0 to 40MHz Flash Programmable 8-bit Microcontroller
• Manufacturer: ATMEL Corporation

T89C51RD2
Boot process summary
The boot process is summarized on the following flowchart:
57
Hardware
Software
Reset Falling Edge
Jump to FC03h
Jump to XX00h
CUSTOM BOOT
Software
Boot Vector ?
Conditions
Hardware
BLJB = 1
LOADER
BSB ?
?
?
No
No
BSB 00h
SBV
FCh
Yes (
Yes
BSB= 0
SBV= FCh
PSEN =0, EA =1, and ALE =1 or not connected)
=
XXh
Figure 21. Boot process flowchart
USER APPLICATION
Jump to 0000h
- BSB: Boot Status Byte
- BLJB: Boot Loader Jump Bit (Hardware Bit set to
0 by default)
Jump to FC00h
DEFAULT BOOT
LOADER
Rev. F - 15 February, 2001