YMF825Board Rev.A

Overview


This is a board with a Yamaha YMF825 (SD-1) mounted on it.
The SD-1 is a 4-operator, 16-voice polyphonic FM synthesizer chip.
Its registers can be controlled directly by SPI. The board has a crystal unit. The chip has a DAC and an amplifier.
You can generate sound by only manipulating the registers.

Features

・3.5mm Headphone jack
・12.288MHz crystal unit
・YMF825 chipset
　・Integrated loudspeaker driver
　・Synchronous serial data link for host controller interface (SPI compatible)
　・FM tone generator
　・Integrated 3-band equalizer
・IOVDD（switching 5V / 3.3V）

Design Data

Schematic

Layout view(Top of view)

Power Supply

Single 5V Power Supply Configuration

No changes to the schematic are necessary.
Please connect the power supply to 5V and GND.
The 3.3V terminal will not be used.

Dual Power Supply(5V/3.3V) Configuration

Please connect a power supply to 3.3V (separately from 5V).
Remove the R0 resistor.
Short S1 with solder.

Specification

Terminal List


	
		Terminal Number / Function Name 
		Description
	
	
		
			0: SS
		
		
			Slave Selection of Serial Interface (Chip Select)
		
	
	
		
			1: MOSI
		
		
			Master Out, Slave In of Serial Interface, Input of YMF825Board
		
	
	
		
			2: MISO
		
		
			Master In, Slave Out of Serial Interface, Output of YMF825Board
		
	
	
		3: SCK
		Serial Interface Clock
	
	
		4: GND
		Ground of referenced voltage
	
	
		5: 5V
		5V power supply input
	
	
		6: RST_N
		Reset the YMF825. Can be left unconnected because the YMF85 has a power-on reset and a software reset function.
	
	
		7: AUDIO
		LINE Output. Refer to the schematic.
	
	
		8: 3.3V
		3.3V power supply input. In the case of the dual power supply.
	

Hardware Specification

	
		Item
		Description
	
	
		
			Speaker Output
		
		
			0.9W 8Ω
		
	
	
		
			Serial Interface
		
		
			MAX 10MHｚ
		
	
	
		
			Vih
		
		
			0.8 x IOVDD
		
	
	
		Vil
		0.2 x IOVDD
	
	
		5V
		4.5V～5.5V
	
	
		3.3V
		3.0V～3.6V
	
	
		Operating temperature range
		-20℃ -- 85℃

Terminal Number / Function Name	Description
0: SS	Slave Selection of Serial Interface (Chip Select)
1: MOSI	Master Out, Slave In of Serial Interface, Input of YMF825Board
2: MISO	Master In, Slave Out of Serial Interface, Output of YMF825Board
3: SCK	Serial Interface Clock
4: GND	Ground of referenced voltage
5: 5V	5V power supply input
6: RST_N	Reset the YMF825. Can be left unconnected because the YMF85 has a power-on reset and a software reset function.
7: AUDIO	LINE Output. Refer to the schematic.
8: 3.3V	3.3V power supply input. In the case of the dual power supply.

Item	Description
Speaker Output	0.9W 8Ω
Serial Interface	MAX 10MHｚ
Vih	0.8 x IOVDD
Vil	0.2 x IOVDD
5V	4.5V～5.5V
3.3V	3.0V～3.6V
Operating temperature range	-20℃ -- 85℃