82375EB Datasheet, PDF (57/131 Pages) Intel Corporation – PCI-EISA BRIDGE (PCEB)

82375EB SB
4 1 4 1 ESC Resident PIC Registers
Access to the 8259 registers are positively decoded if enabled through PDCON Register to minimize access
time to the system interrupt controller during interrupt processing (in particular during the EOI command
sequence) Table 3 shows the 8259 I O address map After PCIRST positively decoded access to these
address ranges is disabled
Address
(hex)
0020h
0021h
00A0h
00A1h
Table 3 ESC Resident Programmable Interrupt Controller (PIC) Registers
Address
Bits
FEDC
Address
Bits
BA98
Address
Bits
7654
Address
Bits
3210
Access
Type
Register Name
0000
0000
001x
xx00
RW
INT 1 Control
0000
0000
001x
xx01
RW
INT 1 Mask
0000
0000
101x
xx00
RW
INT 2 Control
0000
0000
101x
xx01
RW
INT 2 Mask
4 1 4 2 EISA Resident IDE Registers
The PCI address decoder positively decodes IDE I O addresses (Primary and Secondary IDE) that exist within
the EISA subsystem (typically on the X-bus or as an ISA slave) This feature is implemented to minimize the
decoding penalty for the systems that use IDE as a mass-storage controller Table 4 shows IDE’s I O address
map Note that the PDCON Register controls the enable disable function for IDE decoding After PCIRST
positive decode of the IDE address range is disabled
Address
(hex)
0170h
0171h
0172h
0173h
0174h
0175h
0176h
0177h
01F0h
01F1h
01F2h
01F3h
FEDC
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
0000
Table 4 EISA Resident IDE Registers
Addess (Bits)
BA98 7654
3210
Access
Type
Register Name
0001 0111 0000
RW
Secondary Data Register
0001 0111 0001
RW
Secondary Error Register
0001 0111 0010
RW
Secondary Sector Count Register
0001 0111 0011
RW
Secondary Sector Number Register
0001 0111 0100
RW
Secondary Cylinder Low Register
0001 0111 0101
RW
Secondary Cylinder High Register
0001 0111 0110
RW
Secondary Drive head Register
0001
0111 0111 R W
Secondary Status Register
0001
1111 0000 R W
Primary IDE Data Register
0001
1111 0001 R W
Primary Error Register
0001
1111 0010 R W
Primary Sector Count Register
0001
1111 0011 R W
Primary Sector Number Register
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