SAB-C509-LM SIEMENS [Siemens Semiconductor Group], SAB-C509-LM Datasheet - Page 21

• Manufacturer Part Number: SAB-C509-LM
• Description: 8-Bit CMOS Microcontroller
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

C509-L
Programming Mode Configuration
The External Programming Mode is implemented for the in-circuit programming of external 5V-only
FLASH EPROMs. Similar as in the XRAM mode, the Boot ROM, the XRAM, and the external data
memory (SRAM) are mapped into the code memory area, while the external FLASH memory is
mapped into the external data memory area. Additionally to the XRAM mode, the FLASH memory
can also be written through external data memory accesses (MOVX instructions). External program
memory fetches from the SRAM are controlled by the P3.7/RD/PSENX pin. External data memory
read/write accesses from/to the ROM/EPROM are controlled by the PSEN/RDF and P6.3/WRF pin.
Figure 9
Locations of Code- and Data Memory in Programming Mode
Semiconductor Group
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