 SU.HARDW.PC.CPU (2:5020/299)  SU.HARDW.PC.CPU 
 From : Aleksandr Konosevich                2:5004/9        Sat 14 Oct 95 17:36 
 Subj : .,   ?                                                      


p p,   p訢 ﭨ, p  p筮 㬥樨,
p    ...

[...]

Am486(R) Microprocessor Design. Application Notes.

Page 3.

         Table 2. Microprocessor Pinout Differences

Pin # Am486DX4 Future   Am486DX2 Am486DX2 169-pin  i486DX2  i486DX4
      CPU      w/b enh. CPU (5V) CPU (3V) OverDrv  SL-Ehh.
               CPU                        Socket

A-10  INC      INV      INC      INC      INC      INC      INC
A-12  INC      HITM#    INC      INC      INC      INC      INC
A-13  INC      INC      INC      INC      FERR#    INC      INC
B-10  INC      SMI#     INC      INC      SMI#     SMI#     SMI#
B-12  INC      CACHE#   INC      INC      INC      INC      INC
B-13  CLKMUL   WB/WT#   INC      CLKMUL   INC      INC      INC
B-14  TMS      TMS      TMS      TMS      UP#      TMS      TMS
C-10  INC      SRESET   INC      INC      INC      SRESET   SRESET
C-12  INC      SMIACT#  INC      INC      SMIACT#  SMIACT#  SMIACT#
C-14  FERR#    FERR#    FERR#    FERR#    INC      FERR#    FERR#
G-15  INC      STPCLK#  INC      INC      STPCLK#  STPCLK#  STPCLK#
J-1   INC      INC      Vcc      INC      Vcc/Vcc5 Vcc      Vcc5
R-17  INC      CLKMUL   INC      INC    INC/CLKMUL INC      CLKMUL
S-4   VOLDET   VOLDET   NC       VOLDET  NC/VOLDET NC       VOLDET

NOTES :
  1.When using the 237-pin version, refer to the next higher number and
later (i.e. A-13 = B-14)
  2. The INC indicates a design change from NC pinout specification in
the published data sheets.
  3. Pin B-13 MUST BE connected to Vss for proper operation of current
Am486DX2 microprocessor product.
  4. Pin R-17 MUST BE connected to Vss for proper operation of future
Am486DX2 microprocessor products.

>< IMHO, Cx486DX4-GP4  pinout' ⠫ ⥭ i486DX4. , 
><  ⥯p  SMM  hardware-⨯ - a-la Cyrix & a-la SL-Intel,
>< p ⮬ 3  CCR3.

[...]

Page 5.

   Table 1. Processor Revision ID Values in DX Register after RESET

   Processor type       Am486 CPU      i486 CPU

         DX2            043x           043x
         DX4            048x*          048x
   DX2 w/b enh.         047x           047x
   DX4 w/b enh.         049x           N/A

* Initial versions of the Am486DX4 microprocessor have a waiver that
indicates that the CPU ID code matches that of the DX2 processor.

Figure 1. CPU ID Determination

      CHECK FOR ID CODE :
      Read and store DX immediately after RESET
            |
            V
      DETERMINE CPU OPERATING SPEED :
      Run timing loop and store operating speed value.
            |
            V
      IS ID = 043x
      AND SPEED = 100 MHz ?   ---> YES --->  CPU is Am486DX4-100 processor
            |                                with waiver.
            V
            NO
            |
            V
      IS BIT 21 OF EFLAGS     ---> YES --->  CPU is current Am486 processor
      READ ONLY ?                            or early Intel processor. Use
            |                                reported Processor Revision ID.
            V                                NOTE : This CPU does not support
            NO                               the CPUID instruction.
            |
            V
      RUN CPUID INSTRUCTION   ------------>  CPU is current Intel processor
      TO OBTAIN VENDOR AND                   or future AMD processor. See
      CPU ID INFORMATION                     appropriate data sheet for
                                             detailed information.

>< H,  㤠  p  Cyrix' :  ᮤp DIR0 -  p
>< ,   pp.  RESET'    ... :)

                          With best wishes, Aleksandr
---
 * Origin:  ⮣ p p㫨 ... :E (2:5004/9)
 SU.HARDW.PC.CPU (2:5020/299)  SU.HARDW.PC.CPU 
 From : Sergey Kutikin                      2:5020/324.16   Sun 17 Dec 95 06:30 
 Subj : Am5x86...To be continued...?                                            

                              p !
                                      
       "                              CPU ID in DX at Reset  Comments 
       Am5x86 CPU at 133 or 160 MHz   04Exh                  WT Cache
                                      04Fxh                  WB Cache
       Am5x86 CPU at 150 MHz          048xh                  WT Cache
                                      049xh                  WB Cache "

       ("AMD BIOS Development Guide"  CPU Identification Algorithm p.7)

                                               Best regards,Sergey 
--- GEcho 1.11+
 * Origin:  Net v zhizni schastya... (2:5020/324.16)
 