Technical Reference Guide
Compaq Deskpro 4000 and 6000 Personal Computers
featuring the Pentium II Processor
First Edition–- October 1997
4-11
4.3 AGP BUS OVERVIEW
The Accelerated Graphics Port (AGP) bus is specifically designed as a high-performance,
economical interface for graphics adapters. The AGP bus is very similar to the PCI bus in
operation but operates at Host/memory bus speed (i.e., in systems employing the Pentium II 233,
266, or 300 MHz processor the AGP bus operates at 66 MHz). Graphics adapters using the AGP
bus have dedicated pipelined access to system memory. The AGP bus is particularly suited for 3D
graphics adapters by providing a low-latency interface with system memory for storage of texture
data, z-buffering, and alpha blending. The AGP graphics adapter utilizes its local frame buffer
for display image refreshing.
Figure 4–5.
AGP Bus Connector
Table 4–7.
AGP Bus Connector Pinout
Table 4-7.
AGP Bus Connector Pinout
Pin A Signal B Signal Pin A Signal B Signal Pin A Signal B Signal
01 +12 VDC OVRCNT- 23 (Key) (Key) 45 VDD3 VDD3
02 RSVD VDD 24 (Key) (Key) 46 TRDY- DEVSEL-
03 GND VDD 25 (Key) (Key) 47 STOP- NC
04 USBN USBF 26 PAD30 PAD31 48 PME- PERR-
05 GND GND 27 PAD28 PAD29 49 GND GND
06 INTA- INTB- 28 VDD3 VDD3 50 PAR SERR-
07 RESET CLK 29 PAD26 PAD27 51 PAD15 CBE1-
08 GNT- REQ- 30 PAD24 PAD25 52 NC NC
09 VDD3 VDD3 31 GND GND 53 PAD13 PAD14
10 ST1 ST0 32 RSVD AD_STB1 54 PAD11 PAD12
11 RSVD ST2 33 CBE3- PAD23 55 GND GND
12 PIPE- RBF- 34 NC NC 56 PAD09 PAD10
13 GND GND 35 PAD22 PAD21 57 CBE0- PAD08
14 RSVD RSVD 36 PAD20 PAD19 58 NC NC
15 SBA1 SBA0 37 GND GND 59 RSVD AD_STB0
16 VDD3 VDD3 38 PAD18 PAD17 60 PAD06 PAD07
17 SBA3 SBA2 39 PAD16 CBE2- 61 GND GND
18 RSVD SB_STB 40 NC NC 62 PAD04 PAD05
19 GND GND 41 FRAME- IRDY- 63 PAD02 PAD03
20 SBA5 SBA4 42 RSVD RSVD 64 NC NC
21 SBA7 DBA6 43 GND GND 65 PAD00 PAD01
22 (Key) (Key) 44 RSVD RSVD 66 RSVD RSVD
B94
A94
B66
A66
A1
B1
A21 A26
B21 B26
To Next Page
Loading...
