Immediate 20 bitsTo load a 20-bis register from memory would take two operands, but this would waste 12 bits from the second operand. The (RISC like) solution is to embed the most significant nibble (MSN) within the op. code. Therefore, an instruction of this kind takes only one operand from memory and can complete in two machine cycles.
Example:
movi sp, value ; Value is 20 bits but it only takes one 16-bits operand.
; the remaining 4 bits (MSN) is embedded in the op code.
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Homebuilt CPUs WebRing
JavaScript by Qirien Dhaela
Join the ring?
David Brooks, the designer of the Simplex-III homebrew computer, has founded the Homebuilt CPUs Web Ring. To join, drop David a line, mentioning your page's URL. He will then add it to the list.
You will need to copy this code fragment into your page.
Project start date: May 13 of 2009
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