HP A2Y15AV Manual Do Utilizador

160

Datasheet, Volume 2

MMIO_INDEX: A 32 bit I/O write to this port loads the offset of the MMIO register or 
offset into the GTT that needs to be accessed. An I/O Read returns the current value of 
this register. 

This mechanism to access internal graphics MMIO registers must not be used to access 
VGA I/O registers which are mapped through the MMIO space. VGA registers must be 
accessed directly through the dedicated VGA I/O ports.

MMIO_DATA: A 32-bit I/O write to this port is re-directed to the MMIO register/GTT 
location pointed to by the MMIO-index register. A 32-bit I/O read to this port is re-
directed to the MMIO register/GTT location pointed to by the MMIO-index register.

0–3h

Index

MMIO Address Register

00000000h

 RW

4–7h

Data

MMIO Data Register

00000000h

 RW

31:21

RO

0h

20:2

RW

00000h

FLR, 

Uncore

Register/GTT Offset (REGGTTO) 
This field selects any one of the DWord registers within the MMIO 

register space of Device 2 if the target is MMIO Registers.
This field selects a GTT offset if the target is the GTT.

1:0

RW

00b

FLR, 

Uncore

Target (TARG) 
00 = MMIO Registers
01 = GTT
1X = Reserved

31:0

RW

00000000h

FLR, 

Uncore

MMIO Data Window (DATA) 
This field is the data field associated with the IO2MMIO access.