Peripheral Simulation

For CAST, Inc. S8051XC3-C(430) — External & On-Chip Memory

Simulation support for this peripheral or feature is comprised of:

• Accurate simulation of special on-chip features.

These simulation capabilities are described below.

External and On-Chip Memory

On-Chip Memory

• 256 bytes internal data memory.
• 1k bytes external data memory.
• 16k bytes Flash program memory for the DS89C430.
• 32k bytes Flash program memory for the DS89C440.
• 64k bytes Flash program memory for the DS89C450.

The ROMSIZE feature allows your software to configure the maximum address of on-chip Flash program memory. This allows on-chip Flash to act as a bootstrap loader for an external Flash or Nonvolatile SRAM. You may also use the ROMSIZE feature to increase the amount of available program memory from 64KB to 80KB without bank switching.

External Memory

1k bytes of on-chip RAM is available as external data memory possibly eliminating the need for off-chip external RAM. When enabled by software, the MOVX instruction accesses this data memory instead of any off-chip memory that may exist.