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DP offset instructions, new demo programs.

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Added DPUP and DPDN, which take a one byte operand specifying how far up or down to offset the Data Pointer.
Three Fibonacci generators using the print.asm library.
 - 8 bit values printing in decimal representation.
- 16 bit values printing in hexadecimal representation.
- 32 bit values printing in hexadecimal representation.
This commit is contained in:
Anachronaut
2024-11-01 12:13:13 -04:00
committed by GitHub
parent e5241beb51
commit f4c78e68ba
7 changed files with 332 additions and 90 deletions
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Source/Emulator/cpu.c
+59 -56
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@@ -33,27 +33,27 @@ void genericBranch(CPURegisters *cpu){
void genericCall(CPURegisters *cpu){
// Order, low byte, high byte
cpu->Data[cpu->StackPointer] = cpu->ProgramCounter & 0xFF;
cpu->StackPointer--;
cpu->Data[cpu->StackPointer] = (cpu->ProgramCounter >> 8) & 0xFF;
cpu->StackPointer--;
// Push the Data Pointer to the Stack.
// Order, low byte, high byte
cpu->Data[cpu->StackPointer] = cpu->DataPointer & 0xFF;
cpu->StackPointer--;
cpu->Data[cpu->StackPointer] = (cpu->DataPointer >> 8) & 0xFF;
cpu->StackPointer--;
// Push Q to the Stack.
cpu->Data[cpu->StackPointer] = cpu->Q;
cpu->StackPointer--;
// Push B to the Stack.
cpu->Data[cpu->StackPointer] = cpu->B;
cpu->StackPointer--;
// Push A to the Stack.
cpu->Data[cpu->StackPointer] = cpu->A;
cpu->StackPointer--;
// Perform a Generic Branch to the Address.
genericBranch(cpu);
cpu->Data[cpu->StackPointer] = cpu->ProgramCounter & 0xFF;
cpu->StackPointer--;
cpu->Data[cpu->StackPointer] = (cpu->ProgramCounter >> 8) & 0xFF;
cpu->StackPointer--;
// Push the Data Pointer to the Stack.
// Order, low byte, high byte
cpu->Data[cpu->StackPointer] = cpu->DataPointer & 0xFF;
cpu->StackPointer--;
cpu->Data[cpu->StackPointer] = (cpu->DataPointer >> 8) & 0xFF;
cpu->StackPointer--;
// Push Q to the Stack.
cpu->Data[cpu->StackPointer] = cpu->Q;
cpu->StackPointer--;
// Push B to the Stack.
cpu->Data[cpu->StackPointer] = cpu->B;
cpu->StackPointer--;
// Push A to the Stack.
cpu->Data[cpu->StackPointer] = cpu->A;
cpu->StackPointer--;
// Perform a Generic Branch to the Address.
genericBranch(cpu);
}
uint8_t executeOperation(uint8_t Instruction, CPURegisters *cpu) {
@@ -88,33 +88,25 @@ uint8_t executeOperation(uint8_t Instruction, CPURegisters *cpu) {
cpu->Q = cpu->A|cpu->B;
break;
case 0x04:
// NAND - A nand B -> Q
cpu->Q = ~(cpu->A&cpu->B);
break;
case 0x05:
// NOR - A nor B -> Q
cpu->Q = ~(cpu->A|cpu->B);
break;
case 0x06:
// XOR - A xor B -> Q
cpu->Q = cpu->A^cpu->B;
break;
case 0x07:
case 0x05:
// NOTA - not A -> Q
cpu->Q = ~cpu->A;
break;
case 0x08:
case 0x06:
// NOTB - not B -> Q
cpu->Q = ~cpu->B;
break;
case 0x09:
case 0x07:
// SHL - Shift AB left.
shiftRegister = ((uint16_t)cpu->A << 8) | cpu->B;
shiftRegister = (shiftRegister << 1) | (shiftRegister >> 15);
cpu->A = shiftRegister >> 8;
cpu->B = shiftRegister & 0xFF;
break;
case 0x0A:
case 0x08:
// SHR - Shift AB right.
shiftRegister = ((uint16_t)cpu->A << 8) | cpu->B;
shiftRegister = (shiftRegister >> 1) | (shiftRegister << 15);
@@ -167,29 +159,29 @@ uint8_t executeOperation(uint8_t Instruction, CPURegisters *cpu) {
// CALL - Push the Program Counter to the Stack, and perform an immediate branch.
genericCall(cpu);
break;
case 0x18:
// CALLA
if (cpu->A == 0) {
genericCall(cpu);
}
break;
case 0x19:
// CALLB
if (cpu->B == 0) {
genericCall(cpu);
}
break;
case 0x1A:
// CALLQ
if (cpu->Q == 0) {
genericCall(cpu);
}
case 0x1B:
// CALLCF
if (cpu->Status & 0x01) {
genericCall(cpu);
}
break;
// case 0x18:
// // CALLA
// if (cpu->A == 0) {
// genericCall(cpu);
// }
// break;
// case 0x19:
// // CALLB
// if (cpu->B == 0) {
// genericCall(cpu);
// }
// break;
// case 0x1A:
// // CALLQ
// if (cpu->Q == 0) {
// genericCall(cpu);
// }
// case 0x1B:
// // CALLCF
// if (cpu->Status & 0x01) {
// genericCall(cpu);
// }
// break;
case 0x1F:
// RET - Return from subroutine, restore the registers and set the Program Counter to the Return Address.
// Pop A from the Stack.
@@ -213,6 +205,7 @@ uint8_t executeOperation(uint8_t Instruction, CPURegisters *cpu) {
cpu->ProgramCounter = cpu->ProgramCounter | (uint16_t)cpu->Data[cpu->StackPointer];
// Add 2 to the Program Counter to skip over the address when it returns.
cpu->ProgramCounter += 2;
break;
//
// 2x - Register Operations:
@@ -347,6 +340,16 @@ uint8_t executeOperation(uint8_t Instruction, CPURegisters *cpu) {
Address |= (uint16_t)cpu->Program[cpu->ProgramCounter];
cpu-> DataPointer = Address;
break;
case 0x48:
// DPUP - Offset the Data Pointer up by the value of the next byte of Program Memory.
cpu->ProgramCounter++;
cpu->DataPointer += cpu->Program[cpu->ProgramCounter];
break;
case 0x49:
// DPDN - Offset the Data Pointer down by the value of the next byte of Program Memory.
cpu->ProgramCounter++;
cpu->DataPointer -= cpu->Program[cpu->ProgramCounter];
break;
//
// Dx - Output Operations:
//