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發表於 2009-3-19 20:24:07
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非常謝謝大大整理了這麼好的資料,我也不是很懂以下是我的想法是,供電電路完成工作以後緊接著換時鐘晶片提供時間給
CPU AGP PCI RAM 使其激活,時鐘晶片本身要先WORK,這時就是用POWER-SUPPLY所提供的3.3V及MOSFET轉換的2.5V接時鐘晶片上的Vcc時鐘晶片也會有兩隻腳接震盪器(晶振)。不知道這樣是否了解。
原本我今天找的資料如下,看到F大這篇後真是春風化雨呀!
Phoenix BIOS Post Procedures:
CPU Check internal operations i.e. ALE/IRQ status, Request, LA and memory read/write
CMOS RAM Test with walking bit pattern
ROM BIOS Perform checksum on ROM BIOS where all bits are added and compared to a factory set total
PIT Check to ensure interrupt requests are properly executed
DMA Check DMA from CPU to memory without BIOS. Also check page registers
Base 64K Check first 4K block
Serial and Parallel Ports I/O data areas for any devices found are assigned but are not tested
PIC Check that proper interrupt request levels are addressed
Keyboard Controller Check 8240 for proper operation, including scan code response and Gate A20 which allows CPU operation in protected mode
CMOS Check data within CMOS and compare to BIOS information. Failure of the extended area is often due to wrong data setup. Constant failure after resetting CMOS is either battery CMOS chip or RTC
Video Controller Test and initialize controller and ROM on the video adapter
RTC Check to ensure proper frequencies are on proper lines for the Video Color CPU and DMA frequency. Check RTC and PIT or the system crystal if a failure occurs
CPU Return from protected mode. CPU is put into protected mode and returns to the POST at the point indicated by the CMOS ROM data area byte 0F. Failure here is normally due to the CPU, keyboard controller, CMOS chip or an address line
PIC Test counter 2
NMI Check for non maskable interrupt request vector for active status. Failure is normally due to the CMOS but could also be the BIOS IRQ or CPU chips
Keyboard Check for NumLock and/or Caps and Shift keys
Mouse Initialize through the keyboard controller. This is only done if a mouse is present and it is initialized in this way
RAM Above 64K Test in 64KB blocks with a walking bit pattern and parity enabled
Fixed and Floppy Controllers Test for proper response to BIOS calls
Shadow RAM Areas Look in CMOS for settings on which adapter or system ROM's are to be shadowed
Option ROM Look for ROM signatures of 55AA in extended memory then initialize the ROM and halt testing while internal checks are carried out
External Cache Check controller chip for external cache
CPU Internal Cache The CPU's internal cache is tested
Hardware Interrupts Initialize and test video, floppy, hard I/O adapters, serial and parallel ports
Cassette Test internal or external cassette drives
Boot Code Errors Errors occurring after this point are normally a corrupt boot record |
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