Rainbow Electronics T89C5121 - Manual (Page 63)

63
A/T8xC5121
4164G–SCR–07/06
Figure 25. CRAM and ROM Mappings
T83C5121 with Mask ROM
Version In this version, the customer program is masked in 16 Kbytes ROM.
• The customer program is masked in ROM during the final production phase. The
ROM size will be determined at mask generation process depending of the program
size.
In-System Programming The In-System Programming (ISP) mode is only implemented in the following product
versions:
• EEPROM version
• CRAM version
(The ROM product version is masked with the customer program and does not need
ISP mode)
The ISP is used to download an Application program in the device and to run it.
The communication protocols which are implemented are: UART and TWI.
Hardware Interface The hardware in relation with the two communication protocols is detailed below:
• TWI protocol
• Serial protocol
16K bytes
0000h
3FFFh
CRAM XRAM RAM ROM
FFFFh
C000h
Bootloader
F800h entry point
256 bytes 256 bytes