Read Configuration Byte; Read Configuration Word - Xycom XVME-653 Manual

Read Configuration Byte

This function reads individual bytes from the configuration space of the VMEbus inter-
face.
ENTRY:
[AH] BIOS_FUNCTION_ID = B1h
[AL] BIOS_SUBFUNCTION_ID = 08h
[BH] Bus Number (0-255)
[BL] Device Number in upper 5 bits
Function Number is bottom 3 bits
[DI] Register Number (0...255)
EXIT:
[CL] Byte Read
[AH] Return Code:
00h = SUCCESSFUL
87h = BAD_REGISTER_NUMBER
[CF] Completion Status, set = error, reset = success

Read Configuration Word

This function reads individual words from the configuration space of the VMEbus inter-
face. The Register Number parameter must be a multiple of two (i.e., bit 0 must be set to
0).
ENTRY:
[AH] BIOS_FUNCTION_ID = B1h
[AL] BIOS_SUBFUNCTION_ID = 09h
[BH] Bus Number (0-255)
[BL] Device Number in upper 5 bits
Function Number is bottom 3 bits
[DI] Register Number (0, 2, 4, ...254)
EXIT:
[CL] Word Read
[AH] Return Code:
00h = SUCCESSFUL
87h = BAD_REGISTER_NUMBER
[CF] Completion Status, set = error, reset = success
Chapter 4 – Programming
4-9