iRiver H1x0/H3x0 Port Pin Assigments

GPIO

H1x0			H3x0
Port pin	I/O/F	Description	I/O/F	Description
0	F	DDATA0	F	DDATA0
1	F	DDATA1	F	DDATA1
2	F	DDATA2	F	DDATA2
3	O	I2C Clock (to FM tuner) (C)	O	ISP1362 RESET
4	F	DDATA3	F	DDATA3
5	O	EEPROM?	I	ISP1362 INT1
6	O	ISD300 3.3V control	I	PCF50606 IRQ
7	O	ADC CS (C)	I	ISP1362 INT2
8	F	A25	F	A25
9	O	Disk LED control (C)	I	A-B button (0=down)
10	F	BCLK	F	BCLK
11	O	Remote LCD backlight (0 = on) (C)	F	ISP1362 Chip Select
12	O	EEPROM I2C CLK (C)	I/O	EEPROM I2C SCL & PCF50606 SCL (C)
13	F	IDE_DIOR (C)	F	IDE_DIOR
14	F	IDE_DIOW (C)	F	IDE_DIOW
15	F	SCLK_OUT	I	REC button (0=down)
16	O	Remote LCD RS (C)	O	Remote LCD RS
17	F	BUFENB2 (For ATA buffers) (C)	F	BUFENB2 (For ATA buffers)
18	O	ATAEN to ISD300 (1=USB controlled disk) (C)	O	ATAEN to ISD300 (1=USB controlled disk)
19	O	ATA RESET	O	ATA RESET
20	F	TA	F	TA
21	O	ADC Data Out (C)	O	ISP1362 OTGMODE
22	O	SPI CLK (C)	O	ISP1362 D_SUSPEND
23	O	Audio mux select (0=Playback, 1=FM tuner) (C)	I	LX2201 Charge STAT pin (1 = Battery charge in progress)
24	O	ISD300 power (1=on) (C)	I/O	I2C SDA to ISD300 cfg EEPROM
25	F	SDATAO1	I/O	I2C SCL to ISD300 cfg EEPROM
26	F	QSPI_DOUT	O	Goes to an unmounted resistor, R26
27	F*	RXD1 + TXD1	F*	RXD1 + TXD1
28	O*	Remote LCD CLK (C)	I/O*	I: USB host plug pin 4 (ID), O: Remote LCD CLK
29	O	Reset line for I2C?	O	ISP1362 ID
30	I*	I: Remote control detect (0=present) (C)	I*	I: Remote control detect (0=present), O: Audio mux select (0=Playback, 1=FM tuner)
31	I*	ADC Data In (C) & Hard drive power (0=on) (C)	I*	Hard drive power (0=on)

GPIO1

H1x0			H3x0
Port pin	I/O/F	Description	I/O/F	Description
32 (0)		Unassigned		Unassigned
33 (1)	I*	Hold switch (C)	I/O*	In: Hold switch, Out: Remote LCD backlight (0 = on)
34 (2)	O	Remote LCD CS (C)	O	Remote LCD CS
35 (3)	O	LCD A0 (C)	O	ISD300 3.3V control
36 (4)	F*	EBUIN1 + EBUOUT1	I/O*	O: test point TP14
37 (5)	I*	On/Play/Pause key (0=down) (C)	I*	On/Play/Pause key (0=down) (C)
38 (6)	I*	Remote On/Play/Pause key (0=down) (C)	?	NON-lcd remote play/pause (on) key; LCD remote: Navi (joy push); (0=down) (C)
39 (7)	I*	USB detect (C)	I*	USB detect (C)
40 (8)		Unassigned		Unassigned
41 (9)	F*	SDATAI2/SDATAO2
42 (10)	F*	SDATAI4/MCLK2
43 (11)		Unassigned		Unassigned
44 (12)	F	LRCK2
45 (13)	I/O	EEPROM I2C SDA (C)	I/O	EEPROM I2C SDA & PCF50606 SDA (C)
46 (14)	O	LCD RESET (active low) (C)	O	LCD RESET (active low)
47 (15)		Unassigned		Unassigned
48 (16)	F	SCLK2
49 (17)	O	LCD backlight (0 = on) (C)	O	LCD backlight (1 = on)
50 (18)	O	Remote LCD DATA (C)	O	Remote LCD DATA
51 (19)	O	Write 0 at power off	O	Same (C)
52 (20)	I	Remote Hold switch (1=hold) (C)	I	Remote Hold switch (LCD remotes; 1=hold) (C)
53 (21)	F	SUBR	O	Possibly USB Host 5V supply (1 = on)
54 (22)	I	Charger detect (1=inserted) (C)	I	AC Charger detect (1=inserted)
55 (23)	I/O	I2C Data (to FM tuner) (C)
56 (24)	O	S/PDIF Tx diode enable (0=on) (C)	I/O	I2C CLK (to FM tuner)
57 (25)	F	BUFENB1	I/O	I2C SDA (to FM tuner)
58 (26)	F	CS1 (LCD) (C)
59 (27)	F	PST0	F	PST0
60 (28)	F	PST1	F	PST1
61 (29)	F	PST2	F	PST2
62 (30)	F	PST3	F	PST3
63 (31)	F	PSTCLK	F	PSTCLK

"*" indicates that this GPIO or function is actually implemented by two pins on the physical package -- one dedicated input pin and one dedicated output. This means that this logical bit can serve two functions simultaneously. There's only one bit that decides function vs. GPIO, so the composite pin must either both be function pins or a GPI and GPO pin.

"*(C)*" indicates that it is confirmed

PCF50606 GPO

H3x0
Port pin	Description
GPOOD0	High-Z (0x00) enables USB Charging/Power; Low (0x07) disables
GPOOD1	Backlight PWM output
GPOOD2	UDA1380 reset - High-Z (0x00) resets the UDA1380

There is an (obsolete) similar table at IriverMemoryMap which includes information on where in the original firmware you can find usage of these pins.