From 680e6eaf23297fcfef93ff36f54b0d5be4db0b26 Mon Sep 17 00:00:00 2001
From: GabrielTofvesson <gabto095@student.liu.se>
Date: Mon, 8 Apr 2019 20:32:00 +0200
Subject: [PATCH] Add documentation

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+# LMIA advanced development kit
+
+This project was developed as a simple development kit for programming and
+microprogramming the LMIA system.
+
+
+## μASM instruction set
+
+### NOP [reg]
+No-operation. This wastes one clock cycle
+
+
+### MOV [regA] \[regB\]
+Move value in *regA* to *regB*
+
+*This operation uses the bus*
+
+*If regB is LC, no other LC operation can be specified in the same cycle*
+
+
+### MVN {[reg] | [const]}
+Move the inverse of a value (from register or constant) into register **AR**.
+
+*This operation uses the bus*
+
+*If a constant is passed, this operation cannot be parallellized*
+
+
+### MVZ [reg]
+Set **AR** to zero. *reg* is ignored and only prevalent due to a microcompiler
+quirk; expect it to be removed in future releases.
+
+*Sets flags: Z, N*
+
+
+### ADD {[reg] | [const]}
+Add value (from register or constant) to register **AR**.
+
+*This operation uses the bus*
+
+*If a constant is passed, this operation cannot be parallellized*
+
+*Sets flags: Z, N, O, C*
+
+
+### SUB {[reg] | [const]}
+Subtract value (from register or constant) from register **AR**.
+
+*This operation uses the bus*
+
+*If a constant is passed, this operation cannot be parallellized*
+
+*Sets flags: Z, N, O, C*
+
+
+### AND {[reg] | [const]}
+Perform bitwise AND with given value (from register or constant) and register
+**AR**. *reg* is ignored and only prevalent due to a microcompiler quirk;
+expect it to be removed in future releases.
+
+*This operation uses the bus*
+
+*If a constant is passed, this operation cannot be parallellized*
+
+*Sets flags: Z, N*
+
+
+### ORR {[reg] | [const]}
+Perform bitwise Or with given value (from register or constant) and register
+**AR**.
+
+*This operation uses the bus*
+
+*If a constant is passed, this operation cannot be parallellized*
+
+*Sets flags: Z, N*
+
+
+
+### ADN {[reg] | [const]}
+Add value (from register or constant) to register **AR** without updating
+flags.
+
+*This operation uses the bus*
+
+*If a constant is passed, this operation cannot be parallellized*
+
+
+### LSL [reg]
+Performs a logical shift left of **AR**. *reg* is ignored and only prevalent
+due to a microcompiler quirk; expect it to be removed in future releases.
+
+*This operation uses the bus*
+
+*If a constant is passed, this operation cannot be parallellized*
+
+*Sets flags: Z, N, C*
+
+
+### BSL [reg]
+Performs a logical shift left of **AR** and **HR** as if they were one 32-bit
+register where **AR** corresponds to the most-significant bits. *reg* is
+ignored and only prevalent due to a microcompiler quirk; expect it to be
+removed in future releases.
+
+*This operation uses the bus*
+
+*If a constant is passed, this operation cannot be parallellized*
+
+*Sets flags: Z, N, C*
+
+
+### ASR [reg]
+Performs an arithmetic shift right on **AR**. *reg* is ignored and only
+prevalent due to a microcompiler quirk; expect it to be removed in future
+releases.
+
+*This operation uses the bus*
+
+*If a constant is passed, this operation cannot be parallellized*
+
+*Sets flags: Z, N, C*
+
+
+### BSR [reg]
+Performs an arithmetic shift right of **AR** and **HR** as if they were one
+32-bit register where **AR** corresponds to the most-significant bits. *reg* is
+ignored and only prevalent due to a microcompiler quirk; expect it to be
+removed in future releases.
+
+*This operation uses the bus*
+
+*If a constant is passed, this operation cannot be parallellized*
+
+*Sets flags: Z, N, C*
+
+
+### LSR [reg]
+Performs a logical shift right of **AR**. *reg* is ignored and only prevalent
+due to a microcompiler quirk; expect it to be removed in future releases.
+
+*This operation uses the bus*
+
+*If a constant is passed, this operation cannot be parallellized*
+
+*Sets flags: Z, N, C*
+
+
+### ROL [reg]
+Performs an arithmetic rotate right on **AR**. *reg* is ignored and only
+prevalent due to a microcompiler quirk; expect it to be removed in future
+releases.
+
+*This operation uses the bus*
+
+*If a constant is passed, this operation cannot be parallellized*
+
+*Sets flags: Z, N, C*
+
+
+### BRL [reg]
+Performs an arithmetic shift left of **AR** and **HR** as if they were one
+32-bit register where **AR** corresponds to the most-significant bits. *reg* is
+ignored and only prevalent due to a microcompiler quirk; expect it to be
+removed in future releases.
+
+*This operation uses the bus*
+
+*If a constant is passed, this operation cannot be parallellized*
+
+*Sets flags: Z, N, C*
+
+
+### LCSET [const]
+Set **LC** to value of constant.
+
+
+### CONST [const]
+Set **AR** to value of cosntant.
+
+*This operation cannot be parallelized*
+
+
+### INCPC
+Increment value in **PC** by one.
+
+
+### DECLC
+Decrement value in **LC** by one.
+
+
+### CALL [label]
+Move value in **uPC** to **uSP** (**MySPC**) and set value in **uPC** to point
+to the address of the given label.
+
+
+### RET
+Move value in **uSP** (**MySPC**) into **uPC**.
+
+
+### HALT
+Stop execution and set value int **uPC** to 0.
+
+
+### BRA [label]
+Perform an unconditional branch to the address of the given label.
+
+
+### BNZ [label]
+Branch to address of label if **Z-flag** is 0.
+
+
+### BRZ [label]
+Branch to address of label if **Z-flag** is 1.
+
+
+### BRN [label]
+Branch to address of label if **N-flag** is 1.
+
+
+### BRC [label]
+Branch to address of label if **C-flag** is 1.
+
+
+### BRO [label]
+Branch to address of label if **O-flag** is 1.
+
+
+### BLS [label]
+Branch to address of label if **L-flag** is 1.
+
+
+### BNC [label]
+Branch to address of label if **C-flag** is 0.
+
+
+### BNO [label]
+Branch to address of label if **O-flag** is 0.
+
+
+
+## Flags
+Flags - *aside from L* - are set based on ALU operations, so they depend on **AR** and the
+**BUS**. Unless otherwise implied or stated, **AR** refers to the state/value
+of **AR** *after* an ALU operation.
+
+### Z
+Set if **AR** == **BUS**
+
+### N
+Set if sign bit in **AR** is set.
+
+### O
+Set if sign of **AR** differs from signs of both **AR** and **BUS** *before*
+the arithmetic operation.
+
+### C
+Set if **AR** is less than or equal to **AR** *before* the arithmetic
+operation.
+
+### L
+Set if **LC** == 0.