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AP5T/AX5T Special Test Notice

Please refer to following FAQ (Frequently Asked Question) for the special test notice and interesting

features of INTEL TX chipset.

1. TX memory performance.

2. TX DMA/33 performance.

3. SDRAM that can be used.

4. 75/83.3MHz external clock.

5. ACPI new features. (Modem ring-on, OnNow, Suspend to HDD)

6. P55C MMX

7. FCC DoC

Note: FAQ may be updated without notice. If

you cannot find the information that you need in

this appendix, visit our WWW home page,

(address: http://www.aopen.com.tw) and check

the FAQ area and other new information.

Q: What is MMX?

A: MMX is the new single-line multiple-instruction technology of the new Intel Pentium PP/MT (P55C)

CPU. A new Pentium Pro CPU (Klamath) with MMX technology is also expected to be released soon.

The MMX instructions are specifically useful for multimedia applications (such as 3D video, 3D

sound, video conference). The performance can be improved if applications use these instructions. All

AOpen MBs have at least dual power onboard to support PP/MT. It is not necessary to have special

chipset for MMX CPU.

Q: What is PBSRAM (Pipelined Burst SRAM)?

A: For Pentium CPU, the Burst means reading four QWord (Quad-word, 4x16 = 64 bits) continuously

with only the first address decoded by SRAM. The PBSRAM will automatically send the remaining

three QWord to CPU according to predefined sequence. The normal address decoding time for

SRAM is 2 to 3 clocks. This makes the CPU data read timing of four QWord to be at least 3-2-2-2

and a total of 9 clocks if traditional asynchronous SRAM is used. However, with PBSRAM, there is

no need to decode address for rest three Qword. Therefore, data read timing can be 3-1-1-1, that is

equivalent to 6 clocks and is faster than asynchronous SRAM.

Q: What is EDO (Extended Data Output) memory?

A: The EDO DRAM technology of EDO is actually very similar to FPM (Fast Page Mode). Unlike

traditional FPM that tri-states the memory output data to start the pre-charge activity, EDO DRAM

holds the memory data valid until the next memory access cycle, that is similar to pipeline effect and

reduces one clock state.

Q: What is SDRAM (Synchronous DRAM)?

A: The SDRAM is a new generation DRAM technology that allows DRAM to use the same clock as the

CPU host bus (EDO and FPM are asynchronous and do not have clock signal). The idea is the same

Summary of content (8 pages)

PAGE 1
AP5T/AX5T Special Test Notice Please refer to following FAQ (Frequently Asked Question) for the special test notice and interesting features of INTEL TX chipset. 1. TX memory performance. 2. TX DMA/33 performance. 3. SDRAM that can be used. 4. 75/83.3MHz external clock. 5. ACPI new features. (Modem ring-on, OnNow, Suspend to HDD) 6. P55C MMX 7. FCC DoC Note: FAQ may be updated without notice. If you cannot find the information that you need in this appendix, visit our WWW home page, (address: http://www.
PAGE 2
Frequently Asked Questions as "Burst" (refer to the previous Q & A). It requires only one clock for the 2nd, 3rd, and 4th QWord (for example, 5-1-1-1 compares with EDO 5-2-2-2). The SDRAM comes in 64-bit 168-pin DIMM (Dual-in-line Memory Module) and operates at 3.3V. Note that some old DIMMs are made by FPM/EDO and only operate at 5V. Do not confuse them with SDRAM DIMM. AOpen is the first company to support dual-SDRAM DIMMs onboard (AP5V), from Q1 1996.
PAGE 3
Frequently Asked Question Manufacturer Model Suggested CAS Latency Time 5V Tolerance Samsung NEC Micron TI TI KM416S1120AT-G12 D4516161G5-A12-7JF MT4LC1M16E5TG-6 TMS626162DGE -15 TMS626162DGE M-67 2 2 2 2 3 Yes No No Yes Yes Q: Which Pentium chipset has the best performance? A: The performance difference of chipset depends on what kind of DRAM they use and the DRAM timing they support. (They all use PBSRAM, so that the difference is very little at 2nd level cache.
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Frequently Asked Questions Chipset Model DRAM Timing Winstone9 6 Intel 430VX Intel 430HX Intel 430TX Intel 430VX Intel 430TX AP5VM AP53/AP5K AP5T/AX5T AP5VM/AP5V AP5T/AX5T EDO EDO EDO SDRAM SDRAM 6-2-2-2 5-2-2-2 5-2-2-2 6-1-1-1 5-1-1-1 86.1 86.8 87.3 86.6 87.7 Q: Can AP5T/AX5T support 75M and 83.3MHz external CPU clock? A: INTEL TX chipset support only 60/66MHz external (bus) clock. However, we tested the lab pilot sample, it looks good to run 75/83.
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Frequently Asked Question DMA mode 1 30ns 5 150ns DMA mode 2 30ns 4 120ns DMA/33 30ns 4 120ns (1/150ns) x 2byte = 13.3MB/s (1/120ns) x 2byte = 16.6MB/s (1/120ns) x 2byte x2 = 33MB/s Q: What is the performance of Ultra DMA/33? Do we need special driver? A: Currently (Jan 1997), the only Ultra DMA/33 HDD we can test is Quantum 1620AT. It is only a lab pilot run sample and has not been tuned to best performance. The final sample will probably be ready in the middle of Feb.
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Frequently Asked Questions Q: What is ATX Soft Power On/Off and Momentary Switch? A: The Soft Power On of the ATX specification means to provide a standby current for special circuit to wait for wakeup event when main power is off. For example, Infrared wakeup, modem wakeup, or voice wakeup. Currently, the most simple usage is to provide standby current for power switch circuit so that power switch can turn on/off the main power through soft power control pin.
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Frequently Asked Question do the same function, since the ACPI specification is not fully ready. AOpen AX5T/AX58 support Suspend to Hard Disk through BIOS. Note that you have to use AOpen VGA PT60 (S3 Virge), AOpen Modem card F34I (Rockwell), AOpen Sound card S320 (Creative) for Suspend to Hard Disk to work properly. Q: What is the AGP (Accelerated Graphic Port)? A: AGP is a PCI-like bus interface targeted for high-performance 3D graphic.
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Frequently Asked Questions mainboard is more difficult than traditional FCC test. If the mainboard passes DoC test, that means it has very low EMI radiation and you can use any kind of housing (even paper housing). Following is an example of DoC label. Currently, AOpen AX65/AP57/AP5T had passed DoC test.