82374EB Datasheet, PDF (101/208 Pages) Intel Corporation – SYSTEM COMPONENT (ESC)

82374EB 82374SB
Memory Address
Range
FFFE8000h to
FFFEBFFFh
FFFEC000h to
FFFEFFFFh
FFFF0000h to
FFFFFFFFh
Table 3 BIOS Chip Select Enable Table (Continued)
Low BIOS En
1234
xx0x
xx1x
xxx0
xxx1
xxxx
xxxx
High
BIOS
En
x
x
x
x
0
1
ENL
BIOS
En
x
x
x
x
x
x
Low
VGA
BIOS
En
x
x
x
x
x
x
High
VGA
BIOS
En
x
x
x
x
x
x
16M
BIOS
En
x
x
x
x
x
x
LBIOSCS
Asserted
No
Yes
No
Yes
No
Yes
NOTES
1 ‘‘x’’ in the above table represents a don’t care condition
2 All the region control bits for the BIOS space are in the BIOS Chip Select A register and BIOS Chip Select 2 register at
configuration offsets 42h and 43h respectively
4 2 I O Addresses Contained Within The ESC
The ESC integrates functions like DMA Programmable Interrupt Controller and Timers All the compatibility
registers associated with these functions are also integrated into the ESC The ESC also integrates some
additional registers like EISA System ID register in order to reduce the overall chip count in the system
All the registers integrated in the ESC are located in the I O range These are 8-bit registers and are accessed
through the ESC EISA interface The ESC internal registers are at fixed I O locations with the exception of
DMA Scatter-Gather registers The DMA Scatter-Gather registers default to the I O addresses 0410h to
043Fh upon reset These registers can be relocated by programming the Scatter-Gather Relocate Base
Address register The DMA Scatter-Gather registers can be relocated to I O addresses range xx10h-xx3Fh
Registers at I O addresses 70h 372h and 3F2h are shared registers between ESC and external logic Port
70h is duplicated in the Real Time Clock logic Bit 3 of ports 372h and 3F2h reside in the ESC and the other
bits reside in the Floppy Disk Controller Table 4 documents the I O address to the ESC internal registers
Address
(Hex)
0000H
0001h
0002h
0003h
0004h
FEDC
0000
0000
0000
0000
0000
Table 4 ESC I O Register Address Map
Address (Bit)
Type
BA98 7654 3210
Name
0000 000x 0000 R W DMA1 CH0 Base and Current Address
0000 000x 0001 R W DMA1 CH0 Base and Current Count
0000 000x 0010 R W DMA1 CH1 Base and Current Address
0000 000x 0011 R W DMA1 CH1 Base and Current Count
0000 000x 0100 R W DMA1 CH2 Base and Current Address
Block
DMA
DMA
DMA
DMA
DMA
101