Peripheral Simulation

For Dallas Semiconductor DS80C400 — One's Complement Adder

Simulation support for this peripheral or feature is comprised of:

• Accurate simulation of special on-chip features.

These simulation capabilities are described below.

One's Complement Adder

The One's Complement Adder provides an efficient way to calculate a 16-bit checksum. Writing 2 bytes successively to a special SFR (OCAD) triggers a 16-bit one's complement add to an internal accumulator. Writing to this register is repeated, 2 bytes at a time, until the entire data block is checksummed. When the OCAD SFR is read twice, the MSB and LSB, respectively, of the calculated 16-bit checksum is returned.