All the initial modules are now built, it is time to document the list of Micro Instructions.

Here is a map of all the available Micro Instructions assigned to each modules:

[unless specified, all actions are synchronous on the CLOCK_MAIN clock signal]

A register

• CLA : Clear A : reset value to 0 - Asynchronous
• AI : A register In : Load A register value from bus
• AO : A register Out : publish A register value to bus

B register

• CLB : Clear B : reset value to 0 - Asynchronous
• BI : B register In : Load B regisister ter value from bus
• BO : B register Out : publish B register value to bus

ALU & Flags

• CLF : Clear Flags : reset flags value to 0 - Asynchronous
• SUB : Substract function : apply substract function (default is Add)
• SO : ALU Out : pubish ALU result value to bus
• FI : Flags In : set flags based on current value of ALU output

Instruction register

• II : Instruction In : Load instruction register value from bus

Step counter

• CLstep : Clear Steap : reset counter to 0 - synchronous on CLOCK_STEP clock signal

Clock 

• HALT : stops the clock

Program counter

• CLC : Clear Program Counter : reset Program Counter value to 0 - Asynchronous
• CE : Program Counter enable : increment Program Counter value by 1
• CI : Program Counter In : load Programl Counter value from bus
• CO : Program Counter Out : publish Program Counter value to bus

Memory Address Register

• RI : Memory Address Register In : load Memory Address Register value from bus

Memory

• MI : Memory In : Load value from bus and store it in memory at the address specified by the Memory Address Register
• MO : Memory Out : publish value of memory at address defined by the Memory Address Register to the bus

Output Register

• OI : Output In : load Output register value from bus

Some of these signals will be connected to the Instruction Decoder, some are connected to the reset switch only.