Новини світу мікро- та наноелектроніки

4 months ago I shared the progress of our Open Access Health Tracker from V1 to V2. Today I wanted to share the progress from V2 to V3 on a schematic level. And it's massive.

3x3cm PCB, 3 meters of traces and maxing the capabilities of JLCPCB. Plus an additional 2-3 PCBs for sensors not shown. Next up SLP instead of PCB.

I'm designing a fully-automatic turntable from scratch called the Statimatic STM-01, using:

- A Teensy 4.1

- Stepper for tonearm elevation

- Stepper for tonearm azimuth movement

- Stepper for azimuth clutch

- Demultiplexer, to split elevation/azimuth stepper signal

- Multiplexer, to handle input buttons (like "play" or "pause")

- Shift register, to handle output LED statuses

The "turntable" part isn't finished yet (nor is the automatic movement), so I'm just using an AR-XA as the turntable for now.

I like records, and I like making stuff, so I decided I wanted to make a turntable. I know it isn't practical, but hey, I'm having fun with it! Please excuse the absolute mess that is the wiring.

It is open source, though I'm not sure if GitHub links count as self promotion, so I'll play it safe and leave that out.

[group 4b][variant 4b] 0x0_ = MISC Opcode Name Description

0x00	NOP	No operation
0x01	HLT	Halt CPU execution
0x02	INT	Trigger software interrupt
0x03	CLC	Clear carry flag
0x04	SEC	Set carry flag
0x05	CLI	Clear interrupt enable flag (disable interrupts)
0x06	STI	Set interrupt enable flag (enable interrupts)

0x1_ = MOV Opcode Operands Description

0x10	reg, reg	Copy value from register to register
0x11	reg, [mem]	Load value from memory address into register
0x12	[mem], reg	Store register value to memory address
0x13	reg, #imm	Load immediate value into register
0x14	[mem], [mem]	Copy value from memory address to memory address
0x15	[mem], #imm	Store immediate value to memory address
0x16	reg, [reg]	Load value from address held in register (pointer read)
0x17	[reg], reg	Store register value to address held in register (pointer write)

0x2_ = ALU Opcode Name Description

0x20	ADD	Add register to accumulator
0x21	ADC	Add register to accumulator with carry
0x22	SUB	Subtract register from accumulator
0x23	SBB	Subtract register from accumulator with borrow
0x24	AND	Bitwise AND with accumulator
0x25	OR	Bitwise OR with accumulator
0x26	XOR	Bitwise XOR with accumulator
0x27	NOT	Bitwise NOT of accumulator
0x28	CMP	Compare (subtract without storing result, sets flags only)
0x29	INC	Increment register by 1
0x2A	DEC	Decrement register by 1
0x2B	SHL	Shift left, MSB goes to carry, LSB set to 0
0x2C	SHR	Shift right, LSB goes to carry, MSB set to 0
0x2D	ROL	Rotate left through carry, MSB goes to carry, carry goes to LSB
0x2E	ROR	Rotate right through carry, LSB goes to carry, carry goes to MSB

0x3_ = JUMP Opcode Name Description

0x30	JMP	Unconditional jump to address
0x31	JZ	Jump if zero flag set
0x32	JNZ	Jump if zero flag clear
0x33	JC	Jump if carry flag set
0x34	JNC	Jump if carry flag clear
0x35	JS	Jump if sign flag set (result negative)
0x36	JO	Jump if overflow flag set

0x4_ = STACK/CALL Opcode Name Description

0x40	PUSH	Push register onto stack, decrement SP
0x41	POP	Pop value from stack into register, increment SP
0x42	CALL	Push PC onto stack, jump to address
0x43	RET	Pop PC from stack, return to caller
0x44	IRET	Pop PC and flags from stack, return from interrupt handler

Github repo with all docs and files: https://github.com/mrFavoslav/8bit-cpu-MESAx8
The 8-bit ALU might not work perfectly at the moment. I recently moved some parts of the design around, so there's a good chance a few wires got messed up or misaligned in the process. Any feedback or bug catching is highly appreciated!

I'll be posting my progress here and on https://www.favoslav.cz/blog/