8XC251SB

256-Kbyte external memory

128-Kbyte external memory

64-Kbyte external memory. One additional port pin.

64-Kbyte external memory. Compatible with MCS 51 microcontrollers.

External Memory of 8XC251SB except the top eight bytes (FF:FFF8HFF:FFFFH) which are reserved for the configuration array.

External memory of 8XC251SB or on-chip nonvolatile memory (8Kbytes FF:0000H - FF:1FFFH,
16Kbytes FF:0000H - FF:3FFFH).

External Memory

Reserved

External Memory

External memory or with configuration bit EMAP# = 0, addresses in this range
access on-chip code memory in region FF: (16 Kbyte devices only).

External Memory

On-chip RAM (512 bytes 00:0020H - 00:021FH, 1024 bytes 00:0020H -
00:041FH)

On-chip RAM

Storage for R0R7 of Register File