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Add jump-immediate extension to the ISA

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Reid 'arrdem' McKenzie 2023-01-02 23:12:06 -07:00
parent b0260ce315
commit 5487fb66a2
1 changed files with 15 additions and 3 deletions
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18
src/isa.rs
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@ -4,8 +4,16 @@ pub struct Icode {}
impl Icode {
// Official names
pub const BRK: u8 = 0x00u8;
pub const LIT: u8 = 0b10000000; // AKA keep Yes really. Per spec;
pub const LIT2: u8 = 0b10100000; // AKA keep Yes really. Per spec;
// LIT is BRK + flags
pub const LIT: u8 = 0x80; // AKA keep Yes really. Per spec;
pub const LIT2: u8 = 0xa0; // AKA keep Yes really. Per spec;
// Jump-immediate extensions (again BRK + flags)
pub const JMI: u8 = 0x20; // Jump [to] immediate
pub const JCI: u8 = 0x40; // Jump Conditional Immediate
pub const JSI: u8 = 0x60; // Jump Storing Immediate (call)
pub const INC: u8 = 0x01;
pub const POP: u8 = 0x02;
pub const NIP: u8 = 0x03;
@ -63,7 +71,7 @@ impl Icode {
pub const fn nameof(opcode: u8) -> &'static str {
match opcode {
// Nonstandard icodes + extensions
Icode::LIT | Icode::LIT2 => "LIT", // AKA keep Yes really. Per spec,
Icode::LIT | Icode::LIT2 => "LIT", // AKA keep. Yes really. Per spec,
Icode::NOP => "NOP",
// Standard icodes
Icode::BRK => "BRK",
@ -98,6 +106,10 @@ impl Icode {
Icode::ORA => "ORA",
Icode::EOR => "EOR",
Icode::SFT => "SFT",
// Jump immediate extension
Icode::JMI => "JMI",
Icode::JCI => "JCI",
Icode::JSI => "JSI",
_ => Icode::nameof(opcode & 0x1F),
}
}