PCI bridge

Test Application links

The purpose of VGA Test Application

VGA Test Application intends to show that the PCI bridge has enaugh throughput to successfully work in a system with more PCI devices (like PC-based PCI bus).

The main difference between VGA Card and VGA Test Application

VGA Card uses the on-board memory for storing at least one frame buffer. When a part of picture should be changed, then only the modification of frame buffer is written to the PCI Card.

VGA Test Application do not use an on-board memory for storing a frame buffer. FB (frame buffer) driver allocates a part of system memory for storing the whole frame and sets the starting address to the VGA Test Application card which reads the frame buffer through PCI bus every time the screen has to be refreshed (60 times per second = 60 Hz refresh rate).

Characteristics

Test Application includes two cores: PCI Bridge and CRT. PCI Bridge has approximately 1300 slices and 3 Block SelectRAM+ memories, while CRT has approximately 100 slices and 2 Block SelectRAM+ memories. Here you can see the synthesis LOG file. PCI Bridge was synthesised with following characteristics: - GUEST bridge with PCI to Configuration space IMAGE (16MB min), 1 PCI to WB IMAGE (16MB min) and 1 WB to PCI IMAGE (2GB min) - 64 words (32-bit) of WB Read FIFO and 8 words (32-bit) of WB Write FIFO (3 Block SelectRAM+ memories) - 16 words (32-bit) of PCI Read and Write FIFO (Distributed Block SelectRAM) - Address translation was not implemented You can see, how are these characteristics set, in the pci_user_constants.v file.