STG3005A2S STMicroelectronics, STG3005A2S Datasheet - Page 16

• Manufacturer Part Number: STG3005A2S
• Description: 128-BIT 3D MULTIMEDIA ACCELERATOR
• Manufacturer: STMicroelectronics

RIVA128ZX
Figure 3. Basic PCI transaction on AGP
An example of a PCI transaction occurring between an AGP command cycle and return of data is shown
in Figure 4. This shows the smallest number of cycles during which an AGP request can be enqueued, a
PCI transaction performed and AGP read data returned.
Figure 4. PCI transaction occurring between AGP request and data
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PCICBE[3:0]#
PCIDEVSEL#
PCIFRAME#
PCIAD[31:0]
PCIAGPRBF#
AGPST[2:0]
PCIDEVSEL#
PCIFRAME#
PCIAD[31:0]
PCITRDY#
AGPST[2:0]
PCIIRDY#
PCIREQ#
PCIGNT#
AGPPIPE#
PCITRDY#
PCIIRDY#
PCICLK
PCIREQ#
PCICBE#
PCIGNT#
PCICLK
1
111
xxx
1
111
A9
C9
2
111
xxx
2
3
111
bus cmd
address
111
4
3
pci_cmd
address
111
128-BIT 3D MULTIMEDIA ACCELERATOR
5
data_pci
BE[3:0]#
xxx
xxx
data
BE
4
6
xxx
7
xxx
00x
5
8
0000
xxx
D7
xxx
9
6
000
xxx
+1
10