Atmel AT89EVK-01 User Manual page 6

Hardware Description
2.2 T89C5121
Firmware
Reconfiguration
2.2.1 CEIBO MP-51RD2
Programmer
2-8
4325C–SCR–09/04
The program stored in the T89C5121 (Flash version) sends TWI commands to config-
ure the AT83C24 registers at each reset or power on.
If the user wants to modify the AT83C24 configuration, it need to reprogram the
T89C5121 Flash memory by using FLIP/BatchISP software (free download on
www.atmel.com) as described below.
Figure 2-5. T89C5121 In System Programming Description
5V
Power Supply
Waveform
Generator
(14.74 MHz)
The CEIBO "MP-51RD2 Programmer" board is used to interface the RS-232 and the Rx
Tx pins of the T89C5121. This board makes the electrical interface between microcon-
troller signals (5V) and RS-232 signals (12V).
FLIP/BatchISP software
(ATMEL In System Programming software)
RS-232
CEIBO
MP-51RD2 board
EVK01 board
VCC
VSS
XTAL1
Rx, Tx signals (5V)
AT89EVK-01 User Guide