at89c5131a ATMEL Corporation, at89c5131a Datasheet - Page 8

• Manufacturer Part Number: at89c5131a
• Description: Usb Microcontrollers
• Manufacturer: ATMEL Corporation

Figure 3. Low-pin Count Regular Boot Process
Bit ENBOOT in AUXR1 Register is
RESET
Initialized with BLJB Inverted
ENBOOT = 0
Yes
PC = 0000h
BLJB = 1
ENBOOT = 1
PC = F400h
No
No
Yes
P1_CF = FFh
No
No
Yes
P1_CF = P1
P3_CF = FFh
Yes
No
P3_CF = P3
No
Yes
P4_CF = FFh
Yes
No
P4_CF = P4
Yes
BSB = 0
Yes
No
No
SBV < 7Fh
Yes
Start Application
Start User Bootloader
Start Bootloader
AT89C5131A USB Bootloader
8
4287C–USB–11/04