Cirrus Logic GD542x SVGA

IDCHIP.EXE Identifies the Cirrus Logic Video Chip

CL-GD542x Data Book (alt)
CL-GD542x Technical Reference Manual

GD542x IREF Circuit Comparison (and fix)

Planars and Adapters with GD542x
GD542x Comparison
Compatible SOJ DRAM Chips
SOJ DRAM Pinout


Planars and Adapters with GD542x

Planar/Adapter SVGA
Chip
Video Memory BIOS
Stock Expansion Area Image Ver.
IBM SVGA Adapter GD5428 1 MB none 06H6915 1.41
Japanese SVGA Adapter GD5428 1 MB pads for 2x 512 KB 84G7129 1.41
Reply Video Adapter GD5426 1 MB pads for 2x 512 KB 02-10500 1.20
Model 53SLC2 Planar
Model 55LS 486
Reply 55 Planar
GD5426 1 MB pads for 2x 512 KB ? ?
Model 70-Bxx Planar Upg.
Reply 70 Planar
GD5426 1 MB pads for 2x 512 KB 02M3301*
02M3286*
1.20
?
Reply 60/65/80 TurboBoard GD5426 1 MB pads for 2x 512 KB 131-80*
138-80*
1.20
1.41
PC Server 720 Planar GD5429 1 MB none 06H7206 1.41

* Video BIOS and system firmware (POST/BIOS) stored in the same image/chip.


GD542x Comparison

Complete list of features HERE.

Feature GD5426 GD5428 GD5429
Performance
BitBLT Engine Yes Enhanced MM I/O
Zero-wait-state operation Yes Yes Yes
Maximum display memory 2 MB 2 MB 2 MB
Display memory interface 32-bit 32-bit 32-bit
Max. dot clock frequency 80 MHz 80 MHz 86 MHz
Max. MCLK frequency 50 MHz 50 MHz 60 MHz
General
8-bit gray and 3-3-2 RGB DAC modes No Yes Yes
VESA VAFC base support
(for video overlay)
No No Yes
Screen resolution and colors
640 x 480 up to 16M up to 16M up to 16M
800 x 600 up to 64K up to 64K up to 64K
1024 x 768 (interlaced) up to 256 up to 64K up to 64K
1024 x 768 (non-interlaced) up to 256 up to 256 up to 256
1280 x 1024 (interlaced) up to 256 up to 256 up to 256


Compatible SOJ DRAM Chips (from Peter)

The memory modules should be 70 ns or faster. If you are adding extra video memory on the adapter, use chips with the same or lower access time as the existing modules.

ManufacturerPart
FujitsuMB814260
GoldstarGM71C4260
HitachiHM514260
HyundaiHY514260
MicronMT4C16257
MitsubishiM5M44260
MotorolaMCM54260
NECµPD424260
OKIMSM514260(ALS)
SamsungKM416C256 (alt)
Texas InstrumentsTMS45160
ToshibaTC514260

The same chips are used on the PC750, PC720 (Japanese) IBM planars and Reply PowerBoards.


SOJ DRAM Pinout

Pinout of the 256K x 16 DRAM 40-pin SOJ chips.

               /--------------+
        Vcc  --+o 1        40 +-- Vss
        DQ1  --+  2        39 +-- DQ16
        DQ2  --+  3        38 +-- DQ15
        DQ3  --+  4        37 +-- DQ14
        DQ4  --+  5        36 +-- DQ13
        Vcc  --+  6        35 +-- Vss
        DQ5  --+  7        34 +-- DQ12
        DQ6  --+  8        33 +-- DQ11
        DQ7  --+  9        32 +-- DQ10
        DQ8  --+ 10        31 +-- DQ9
        nc   --+ 11        30 +-- nc
        nc   --+ 12        29 +-- CASL#
        WE#  --+ 13        28 +-- CASH#
        RAS# --+ 14        27 +-- OE#
        nc   --+ 15        26 +-- A8
        A0   --+ 16        25 +-- A7
        A1   --+ 17        24 +-- A6
        A2   --+ 18        23 +-- A5
        A3   --+ 19        22 +-- A4
        Vcc  --+ 20        21 +-- Vss
               +--------------+

Vcc = +5V DC, Vss = GND
Signal marked with # are active LOW.
Source: Micron Technology Inc. Datasheet, ASCII Art by PHW.

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