EverDrive-64 v3

Basic information

ROM: Max 64MiB

RTC: supported

Save: 4k/16k bit EEPROM, 32KiB/128KiB SRAM, 128KiB Flash

USB Serial: 512-bytes block read-write

Registers

All registers must be accessed by 32bit word, but it seems only lower 16bits are valid.

High 16bits of all registers seems REG_STATUS on read.

Base PI address for registers is 0x08040000 (Cartridge Domain 2, SRAM area +0x40000)

You should access these registers from CPU through no-cached segment, i.e. +0xA0000000, ex. 0xA8040020 for REG_KEY.

PI address	name	R/W	description
0x08040000	REG_CFG	R/W	ED64 general configurations
0x08040004	REG_STATUS	R	ED64 registers, SPI, DMA statuses
0x08040008	REG_DMA_LEN	W	SD/USB DMA length in 512bytes blocks - 1 (ex. 0 = 0x200 bytes)
0x0804000C	REG_DMA_RAM_ADDR	W	SD/USB Cart address in 2048bytes blocks (ex. 1 = 0x00000800)
0x08040010	REG_MSG	?	?
0x08040014	REG_DMA_CFG	W	Invoke SD/USB DMA
0x08040018	REG_SPI	R/W	SPI DAT/CMD (write invoke CLK)
0x0804001C	REG_SPI_CFG	W	SPI configurations
0x08040020	REG_KEY	W	Enable or disable ED64 registers
0x08040024	REG_SAV_CFG	W	Save configurations (EEPROM/SRAM/FLASH)
0x08040028	REG_SEC	?	?
0x0804002C	REG_VER	R	Hardware version
0x08040030	?	R/W	I2C to access RTC
0x08040034	?	?	?
0x08040038	?	?	?
0x0804003C	?	?	?
0x08040040	REG_CFG_CNT	?	FPGA?
0x08040044	REG_CFG_DAT	?	FPGA?
0x08040048	MAX_MSG	R/W	Some configurations
0x0804004C	REG_CRC	?	?
0x08040050	?	?	Flash?
0x08040054	?	?	Flash?

0x08040000 (REG_CFG)

Read/Write

bit from lsb	description
15	1=start FPGA configuration??
9-8	D64 specific??
6-5	I2C/RTC??
3	WR_ADDR_MASK??
2	WR_MOD??
1	1=16bit swap on SD DMA read
0	1=enable SDRAM on cart (usually set to 1)

0x08040004 (REG_STATUS)

Read only

bit from lsb	description
15	1=SDRAM enabled?
4	SPI?
3	RXF# on USB FIFO (0=some data from Host exists)
2	TXE# on USB (0=able to send some data to Host)
1	DMATOUT (1=last DMA was timed out, i.e. last transfer is less than 512bytes)
0	DMABUSY (1=DMA is ongoing)

0x08040008 (REG_DMA_LEN)

Write only

Next SD/USB DMA transfers (this + 1) * 512 bytes.

ex. 0 = 0x200 bytes, 1 = 0x400 bytes, 2 = 0x600 bytes.

0x0804000C (REG_DMA_RAM_ADDR)

Write only

Next SD/DMA DMA transfers from this * 2048 bytes.

ex. 0 = 0x00000000, 1 = 0x00000800, 2 = 0x00001000.

This is ED64 ROM address space, ex. 0xB0000000 on CPU = 0x10000000 on PI = 0x00000000 on ED64 ROM.

0x08040010 (REG_MSG)

TBA

0x08040014 (REG_DMA_CFG)

Write only

value	description
1	SD -> Cart
2	Cart -> SD
3	USB -> Cart
4	Cart -> USB

Note that above table numbers are value, not "bit from lsb".

You must set REG_DMA_LEN and REG_DMA_RAM_ADDR before writing this register.

0x08040018 (REG_SPI)

Read/Write

bit from lsb	description
7-0	dat/cmd value. Bits are shifted in from lsb if 1bit mode.

Writing value to this invokes clock CLK on SD card.

You should also write this to read. (write value is ignored)

0x0804001C (REG_SPI_CFG)

Write only

bit from lsb	description
5	Bits transferred on writing REG_SPI: 0=8bits 1=1bit
4	Which line to R/W: 0=CMD 1=DAT
3	Read or write: 0=write 1=read
2	Slave Select line on SD card
1-0	CLK speed: 10=init 01=25MHz 00=50MHz

0x08040020 (REG_KEY)

Write only

TBA

0x08040024 (REG_SAV_CFG)

Write only

TBA

0x08040028 (REG_SEC)

TBA

0x0804002C (REG_VER)

Read only

TBA

0x08040030 (I2C/RTC)

Read/Write

TBA

0x08040040 (REG_CFG_CNT)

TBA

0x08040044 (REG_CFG_DAT)

TBA

0x08040048 (REG_MAX_MSG)

Read/Write

TBA

0x0804004C (REG_CRC)

TBA

USB Serial Communication

Common Code

Before communication, you must enable ED64 registers.

TBA

Sending Data to the Host

You should transfer data from RDRAM to some area on cart "ROM" area first, then use Cart->USB DMA on ED64.

TBA

Reading Data from the Host

You should use USB->Cart DMA on ED64 first, then transfer data from cart ROM area to RDRAM.

TBA