diff options
| -rw-r--r-- | src/peripherals/twi.spec.ts | 77 |
1 files changed, 46 insertions, 31 deletions
diff --git a/src/peripherals/twi.spec.ts b/src/peripherals/twi.spec.ts index 7d5fbf3..f47449b 100644 --- a/src/peripherals/twi.spec.ts +++ b/src/peripherals/twi.spec.ts @@ -5,6 +5,25 @@ import { avrInstruction } from '../cpu/instruction'; const FREQ_16MHZ = 16e6; +// CPU registers +const R16 = 16; +const R17 = 17; +const SREG = 95; + +// TWI Registers +const TWBR = 0xb8; +const TWSR = 0xb9; +const TWDR = 0xbb; +const TWCR = 0xbc; + +// Register bit names +const TWIE = 1; +const TWEN = 4; +const TWSTO = 0x10; +const TWSTA = 0x20; +const TWEA = 0x40; +const TWINT = 0x80; + function asmProgram(source: string) { const { bytes, errors, lines } = assemble(source); if (errors.length) { @@ -16,8 +35,8 @@ function asmProgram(source: string) { function runInstructions(cpu: CPU, twi: AVRTWI, count: number) { for (let i = 0; i < count; i++) { if (cpu.progMem[cpu.pc] === 0x9598) { - console.log(cpu.data[0xbc].toString(16)); - console.log(cpu.data[16]); + console.log(cpu.data[TWCR].toString(16)); + console.log(cpu.data[R16]); throw new Error('BREAK instruction encountered'); } avrInstruction(cpu); @@ -26,35 +45,31 @@ function runInstructions(cpu: CPU, twi: AVRTWI, count: number) { } describe('TWI', () => { - const TWINT = 7; - const TWSTA = 5; - const TWEN = 2; - it('should correctly calculate the sclFrequency from TWBR', () => { const cpu = new CPU(new Uint16Array(1024)); const twi = new AVRTWI(cpu, twiConfig, FREQ_16MHZ); - cpu.writeData(0xb8, 0x48); // TWBR <- 0x48 - cpu.writeData(0xb9, 0); // TWSR <- 0 (prescaler: 1) + cpu.writeData(TWBR, 0x48); + cpu.writeData(TWSR, 0); // prescaler: 1 expect(twi.sclFrequency).toEqual(100000); }); it('should take the prescaler into consideration when calculating sclFrequency', () => { const cpu = new CPU(new Uint16Array(1024)); const twi = new AVRTWI(cpu, twiConfig, FREQ_16MHZ); - cpu.writeData(0xb8, 0x03); // TWBR <- 0x03 - cpu.writeData(0xb9, 0x01); // TWSR <- 1 (prescaler: 4) + cpu.writeData(TWBR, 0x03); + cpu.writeData(TWSR, 0x01); // prescaler: 4 expect(twi.sclFrequency).toEqual(400000); }); it('should trigger data an interrupt if TWINT is set', () => { const cpu = new CPU(new Uint16Array(1024)); const twi = new AVRTWI(cpu, twiConfig, FREQ_16MHZ); - cpu.writeData(0xbc, 0x81); // TWCR <- TWINT | TWIE - cpu.data[95] = 0x80; // SREG: I------- + cpu.writeData(TWCR, TWINT | TWIE); + cpu.data[SREG] = 0x80; // SREG: I------- twi.tick(); expect(cpu.pc).toEqual(0x30); // 2-wire Serial Interface Vector expect(cpu.cycles).toEqual(2); - expect(cpu.data[0xbc] & 0x80).toEqual(0); // UCSR0A should clear TWINT + expect(cpu.data[TWCR] & TWINT).toEqual(0); }); describe('Master mode', () => { @@ -62,7 +77,7 @@ describe('TWI', () => { const cpu = new CPU(new Uint16Array(1024)); const twi = new AVRTWI(cpu, twiConfig, FREQ_16MHZ); jest.spyOn(twi.eventHandler, 'start'); - cpu.writeData(0xbc, (1 << TWINT) | (1 << TWSTA) | (1 << TWEN)); + cpu.writeData(TWCR, TWINT | TWSTA | TWEN); twi.tick(); expect(twi.eventHandler.start).toHaveBeenCalledWith(false); }); @@ -72,15 +87,15 @@ describe('TWI', () => { // https://ww1.microchip.com/downloads/en/DeviceDoc/ATmega48A-PA-88A-PA-168A-PA-328-P-DS-DS40002061A.pdf const { program } = asmProgram(` ; register addresses - _REPLACE TWSR, 0xb9 - _REPLACE TWDR, 0xbb - _REPLACE TWCR, 0xbc + _REPLACE TWSR, ${TWSR} + _REPLACE TWDR, ${TWDR} + _REPLACE TWCR, ${TWCR} ; TWCR bits - _REPLACE TWEN, 0x04 - _REPLACE TWSTO, 0x10 - _REPLACE TWSTA, 0x20 - _REPLACE TWINT, 0x80 + _REPLACE TWEN, ${TWEN} + _REPLACE TWSTO, ${TWSTO} + _REPLACE TWSTA, ${TWSTA} + _REPLACE TWINT, ${TWINT} ; TWSR states _REPLACE START, 0x8 ; TWI start @@ -209,22 +224,22 @@ describe('TWI', () => { // Step 5: wait for the assembly code to indicate success by settings r17 to 0x42 runInstructions(cpu, twi, 16); - expect(cpu.data[17]).toEqual(0x42); + expect(cpu.data[R17]).toEqual(0x42); }); it('should successfully receive a byte from a slave', () => { const { program } = asmProgram(` ; register addresses - _REPLACE TWSR, 0xb9 - _REPLACE TWDR, 0xbb - _REPLACE TWCR, 0xbc + _REPLACE TWSR, ${TWSR} + _REPLACE TWDR, ${TWDR} + _REPLACE TWCR, ${TWCR} ; TWCR bits - _REPLACE TWEN, 0x04 - _REPLACE TWSTO, 0x10 - _REPLACE TWSTA, 0x20 - _REPLACE TWEA, 0x40 - _REPLACE TWINT, 0x80 + _REPLACE TWEN, ${TWEN} + _REPLACE TWSTO, ${TWSTO} + _REPLACE TWSTA, ${TWSTA} + _REPLACE TWEA, ${TWEA} + _REPLACE TWINT, ${TWINT} ; TWSR states _REPLACE START, 0x8 ; TWI start @@ -384,7 +399,7 @@ describe('TWI', () => { // Step 6: wait for the assembly code to indicate success by settings r17 to 0x42 runInstructions(cpu, twi, 16); - expect(cpu.data[17]).toEqual(0x42); + expect(cpu.data[R17]).toEqual(0x42); }); }); }); |