PM_Registers

Register Overview

The Pokemon Mini maps $2000 ~ $20FF as hardware control registers. This area is reserved for hardware related functions such as video, audio, general purpose timers, hardware I/O and system control.

Much of this address space is mapped as Open-Bus, leading us to beleive that this area is not used for any purpose. Other areas respond to requests but their purpose is yet undetermined.

Registers tend to be controlled on a bit level, so for the sanity purposes, they will be broken down to this level. At any point they are shown spanning multiple columns, that indicates that it is a multi-bit value and should be treated as if they were a number.

The bits themselves come in four flavors: Read-only, Write-Only, Read-Write, and S-R Strobe. Write-Only registers typically return a zero value, and are generally only used for things such as resetting timers. S-R Strobes are used for clearing interrupt events, writting a logical '1' to any bit that is set will result in a bit being cleared, where as '0' leaves them unchanged. Unused bits always return '0'.

Any register not included on this list reads as Open-Bus and will be excluded unless a function has otherwise been determined.

Register Mapping

Unused	Read/Write	Read Only	Write Only	S-R Strobe	Read/Write (BIOS, Software only)	Unknown (Read/Write)	Unknown (Weird)	Unknown (Unused)

Register Map Legend

Registers ($2000 to $20FF)

Address	Register	Const Name	< Bit 7 >	< Bit 6 >	< Bit 5 >	< Bit 4 >	< Bit 3 >	< Bit 2 >	< Bit 1 >	< Bit 0 >
$00	System Control 1	SYS_CTRL1	Startup Contrast	Cartridge I/O Enable	LCD I/O Enable
$01	System Control 2	SYS_CTRL2	Ram vector	Int abort	Enable cart interrupts	Power on reset	Cart type
$02	System Control 3	SYS_CTRL3	Cart power state	Cart power required	Suspend mode	???	RTC Timer valid	???
$08	Second Counter Control	SEC_CTRL		Reset	Enable
$09	Second Counter Low	SEC_CNT_LO	Counter
$0A	Second Counter Middle	SEC_CNT_MID	Counter
$0B	Second Counter High	SEC_CNT_HI	Counter
$10	Battery Sensor	SYS_BATT		Low Battery	Battery ADC control	Battery ADC threshold value
$18	Timer 1 Prescalars	TMR1_SCALE	Enable Hi	Hi Scalar	Enable Lo	Lo Scalar
$19	Timers Osc. Enable Timer 1 Osc. Select	TMR1_ENA_OSC TMR1_OSC		Enable Osc. 1	Enable Osc. 2		2nd Osc. (Hi)	2nd Osc. (Lo)
$1A	Timer 2 Prescalars	TMR2_SCALE	Enable Hi	Hi Scalar	Enable Lo	Lo Scalar
$1B	Timer 2 Osc. Select	TMR2_OSC		2nd Osc. (Hi)	2nd Osc. (Lo)
$1C	Timer 3 Prescalars	TMR3_SCALE	Enable Hi	Hi Scalar	Enable Lo	Lo Scalar
$1D	Timer 3 Osc. Select	TMR3_OSC		2nd Osc. (Hi)	2nd Osc. (Lo)
$20	IRQ Priority 1	IRQ_PRI1	IRQ $03 ~ $04	IRQ $05 ~ $06	IRQ $07 ~ $08	IRQ $09 ~ $0A
$21	IRQ Priority 2	IRQ_PRI2	IRQ $0B ~ $0E	IRQ $13 ~ $14	IRQ $15 ~ $1C	IRQ ??? ($1D ~ $1F?)
$22	IRQ Priority 3	IRQ_PRI3		IRQ $0F~$10
$23	IRQ Enable 1	IRQ_ENA1	IRQ $03	IRQ $04	IRQ $05	IRQ $06	IRQ $07	IRQ $08	IRQ $09	IRQ $0A
$24	IRQ Enable 2	IRQ_ENA2		IRQ $0B	IRQ $0C	IRQ $0D	IRQ $0E	IRQ $13	IRQ $14
$25	IRQ Enable 3	IRQ_ENA3	IRQ $15	IRQ $16	IRQ $17	IRQ $18	IRQ $19	IRQ $1A	IRQ $1B	IRQ $1C
$26	IRQ Enable 4	IRQ_ENA4	IRQ $0F	IRQ $10	IRQ ???	IRQ ???		IRQ $1D	IRQ $1E	IRQ $1F
$27	IRQ Active 1	IRQ_ACT1	IRQ $03	IRQ $04	IRQ $05	IRQ $06	IRQ $07	IRQ $08	IRQ $09	IRQ $0A
$28	IRQ Active 2	IRQ_ACT2		IRQ $0B	IRQ $0C	IRQ $0D	IRQ $0E	IRQ $13	IRQ $14
$29	IRQ Active 3	IRQ_ACT3	IRQ $15	IRQ $16	IRQ $17	IRQ $18	IRQ $19	IRQ $1A	IRQ $1B	IRQ $1C
$2A	IRQ Active 4	IRQ_ACT4	IRQ $0F	IRQ $10	IRQ ???	IRQ ???		IRQ $1D	IRQ $1E	IRQ $1F
$30	Timer 1 Control (Lo)	TMR1_CTRL_L	16-bit Mode		???	Enable	Reset	???
$31	Timer 1 Control (Hi)	TMR1_CTRL_H		???	Enable	Reset	???
$32	Timer 1 Preset (Lo)	TMR1_PRE_L	Preset
$33	Timer 1 Preset (Hi)	TMR1_PRE_H	Preset
$34	Timer 1 Pivot (Lo)	TMR1_PVT_L	Pivot
$35	Timer 1 Pivot (Hi)	TMR1_PVT_H	Pivot
$36	Timer 1 Count (Lo)	TMR1_CNT_L	Count
$37	Timer 1 Count (Hi)	TMR1_CNT_H	Count
$38	Timer 2 Control (Lo)	TMR2_CTRL_L	16-bit Mode		???	Enable	Reset	???
$39	Timer 2 Control (Hi)	TMR2_CTRL_H		???	Enable	Reset	???
$3A	Timer 2 Preset (Lo)	TMR2_PRE_L	Preset
$3B	Timer 2 Preset (Hi)	TMR2_PRE_H	Preset
$3C	Timer 2 Pivot (Lo)	TMR2_PVT_L	Pivot
$3D	Timer 2 Pivot (Hi)	TMR2_PVT_H	Pivot
$3E	Timer 2 Count (Lo)	TMR2_CNT_L	Count
$3F	Timer 2 Count (Hi)	TMR2_CNT_H	Count
$40	256Hz Timer Control	TMR256_CTRL		Reset	Enable
$41	256Hz Timer Counter	TMR256_CNT	Count
$44	Unknown		???	???	???
$45	Unknown		???	???	???	???	???
$46	Unknown		???
$47	Unknown		???	???
$48	Timer 3 Control (Lo)	TMR3_CTRL_L	16-bit Mode		???	Enable	Reset	???
$49	Timer 3 Control (Hi)	TMR3_CTRL_H		???	Enable	Reset	???
$4A	Timer 3 Preset (Lo)	TMR3_PRE_L	Preset
$4B	Timer 3 Preset (Hi)	TMR3_PRE_H	Preset
$4C	Timer 3 Pivot (Lo)	TMR3_PVT_L	Pivot
$4D	Timer 3 Pivot (Hi)	TMR3_PVT_H	Pivot
$4E	Timer 3 Count (Lo)	TMR3_CNT_L	Count
$4F	Timer 3 Count (Hi)	TMR3_CNT_H	Count
$50	Unknown		???
$51	Unknown		???	???
$52	Key-Pad Status (Active 0)	KEY_PAD	Power	Right	Left	Down	Up	C	B	A
$53	Cart Bus	CART_BUS		CARD_N
$54	Unknown		???	???	???	???
$55	Unknown		???	???
$60	I/O Direction Select	IO_DIR	???	???	IR Disable	Rumble	EEPROM Clock	EEPROM Data	IR Rx	IR Tx
$61	I/O Data Register	IO_DATA	???	???	IR Disable	Rumble	EEPROM Clock	EEPROM Data	IR Rx	IR Tx
$62	Unknown		???	???
$70	Audio Control	AUD_CTRL		???	Mutes audio if not 0!?
$71	Audio Volume	AUD_VOL		Cart Power (1=Off;0=On)	Volume
$80	PRC Stage Control	PRC_MODE		Map Size	Ena Copy	Ena Sprites	Ena Map	Invert Map
$81	PRC Rate Control	PRC_RATE	Frame counter	Rate divider	???
$82	PRC Map Tile Base Low	PRC_MAP_LO	Map Tile Base
$83	PRC Map Tile Base Middle	PRC_MAP_MID	Map Tile Base
$84	PRC Map Tile Base High	PRC_MAP_HI		Map Tile Base
$85	PRC Map Vertical Scroll	PRC_SCROLL_Y		Map Scroll Y
$86	PRC Map Horizontal Scroll	PRC_SCROLL_X		Map Scroll X
$87	PRC Sprite Tile Base Low	PRC_SPR_LO	Sprite Tile Base
$88	PRC Sprite Tile Base Middle	PRC_SPR_MID	Sprite Tile Base
$89	PRC Sprite Tile Base Hi	PRC_SPR_HI		Sprite Tile Base
$8A	PRC Counter	PRC_CNT		Count
$8B	Unknown (returns 0)
$8C	Unknown (returns 0)
$8D	Unknown (returns 0)
$8E	Unknown (returns 0)
$8F	Unknown (returns 0)
$F0	Unknown (returns 0)
$F1	Unknown (returns 0)
$F2	Unknown (returns 0)
$F3	Unknown (returns 0)
$F4	Unknown (returns 0)
$F5	Unknown (returns 0)
$F6	Unknown (returns 0)
$F7	Unknown (returns 0)
$FE	LCD Raw Control Byte	LCD_CTRL	LCD Control I/O
$FF	LCD Raw Data Byte	LCD_DATA	LCD Data I/O