W83877 Winbond Electronics Corp America, W83877 Datasheet - Page 99

• Manufacturer Part Number: W83877
• Description: Winbond I/O
• Manufacturer: Winbond Electronics Corp America

8.2.30 Configuration Register 25 (CR25)
When the device is in Extended Function mode and EFIR is 25H, the CR25 register can be accessed
through EFDR. Default = BEH if CR16 bit 2 = 1; default = 00H if CR16 bit 2 = 0. The bit definitions
are as follows:
This register is used to select the base address of the UART B from 100H-3F8H on 8-byte
boundaries. NCS = 0 and A10 = 0 are required to access the UART B registers. A[2:0] are don't-care
conditions.
URBAD7-URBAD1 (bit 7-bit 1): match A[9:3]. Bit 7 = 0 and bit 6 = 0 disable this decode.
Bit 0: Reserved, fixed at zero.
8.2.31 Configuration Register 26 (CR26)
When the device is in Extended Function mode and EFIR is 26H, the CR26 register can be accessed
through EFDR. Default = 23H if CR16 bit 2 = 1; default = 00H if CR16 bit 2 = 0. The bit definitions are
as follows:
FDCDQS3-FDCDQS0 (bit 7-bit 4): Allocate DMA resource for FDC.
PRTDQS3-PRTDQS0 (bit 3-bit 0): Allocate DMA resource for PRT.
bit 7- bit4, bit 3 - bit 0
0000
0001
0010
0011
7
7
6
6
5
5
4
4
DMA selected
- 99 -
3
3
DMA_A
DMA_B
DMA_C
None
2
2
1
1
0
0
Publication Release Date: January 1996
Reserved
URBAD1
URBAD2
URBAD3
URBAD4
URBAD5
URBAD6
URBAD7
PRTDQS0
PRTDQS1
PRTDQS2
PRTDQS3
FDCDQS0
FDCDQS1
FDCDQS2
FDCDQS3
W83877F
Revision A2