Specifications

144 AMD Geode™ GeodeROM Functional Specification
System Services
32087C
12.1.10.14 Subfunction 31h - SCxxxx Read ACCESS.bus Device
Description:
Read a byte of data from an ACCESS.bus device when a single chip device is used in the system (i.e., SC1100,
SC1200, SC1201, SC2200, SC3200).
Passed:
Returns:
Related Functions:
None.
12.1.10.15 Subfunction 32h - SCxxxx Write ACCESS.bus Device
Description:
Write a byte of data from an ACCESS.bus device when a single chip device is used in the system (i.e., SC1100,
SC1200, SC1201, SC2200, SC3200).
Passed:
Parameter Description
AX BE31h
BX 4E53h (= ‘NS’)
CH Chip Address
CL Number of bytes
ES:DI Pointer to buffer (if CL > 04h)
Parameter Description
EAX Data read if CL <= 04h
ES:DI Data read if CL > than 04h
CF 0 if operation completed successfully
1 if operation failed; error reported in AH
AH Error code:
01h = Invalid size
02h = ACCESS.bus COM error
03h = Buffer address wrap
Parameter Description
AX BE32h
BX 4E53h (= ‘NS’)
CH Chip address
CL Number of bytes
EDX Data written if CL <= 04h
ES:DI Pointer to buffer (if CL > 04h)