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參數資料
型號： W83877AF
廠商： WINBOND ELECTRONICS CORP
元件分類： 外設及接口
英文描述： Multi-Function I/O Port Controller(多功能輸入／輸出口控制器)
中文描述： MULTIFUNCTION PERIPHERAL, PQFP100
封裝： QFP-100
文件頁數： 106/171頁
文件大?。?/td> 1634K
代理商： W83877AF
W83877AF
Publication Release Date: Dec. 1996
Preliminary Version 0.52
- 104 -
HEFRAS
HEFERE
address and value
0
0
write 88H to the location 250H
0
1
write 89H to the location 250H (power-on default)
1
0
write 86H to the location 3F0H twice
1
1
write 87H to the location 3F0H twice
First, a specific value must be written once (88H/89H) or twice (86H/87H) to the Extended Functions
Enable Register (I/O port address 250H or 3F0H). Second, an index value (00H-17H, 1EH, 20H-29H)
must be written to the Extended Functions Index Register (I/O port address 251H or 3F0H) to identify
which configuration register is to be accessed. The designer can then access the desired
configuration register through the Extended Functions Data Register (I/O port address 252H or 3F1H).
After programming of the configuration register is finished, an additional value should be written to
EFERs to exit the Extended Function mode to prevent unintentional access to those configuration
registers. In the case of EFER at 250H, this additional value can be any value other than 88H if
HEFERE = 0 and 89H if HEFERE = 1. While EFER is at 3F0H, this additional value must be AAH.
The designer can also set bit 6 of CR9 (LOCKREG) to high to protect the configuration registers
against accidental accesses.
The configuration registers can be reset to their default or hardware settings only by a cold reset (pin
MR = 1). A warm reset will not affect the configuration registers.
8.1 Extended Functions Enable Registers (EFERs)
After a power-on reset, the W83877AF enters the default operating mode. Before the W83877AF
enters the extended function mode, a specific value must be programmed into the Extended Function
Enable Register (EFER) so that the extended function register can be accessed. The Extended
Function Enable Registers are write-only registers. On a PC/AT system, their port addresses are
250H or 3F0H (as described in the above section).
8.2 Extended Function Index Registers (EFIRs), Extended Function Data Registers
(EFDRs)
After the extended function mode is entered, the Extended Function Index Register (EFIR) must be
loaded with an index value (0H, 1H, 2H, ..., or 29H) to access Configuration Register 0 (CR0),
Configuration Register 1 (CR1), Configuration Register 2 (CR2), and so forth through the Extended
Function Data Register (EFDR). The EFIRs are write-only registers with port address 251H or 3F0H
(as described in section 8.0) on PC/AT systems; the EFDRs are read/write registers with port address
252H or 3F1H (as described in section 8.0) on PC/AT systems. The function of each configuration
register is described below.
相關PDF資料
PDF描述
W83877ATD enhanced version from Winbonds most popular I/O chip W83877F
W83877ATF enhanced version from Winbonds most popular I/O chip W83877F
W83877 WINBOND I/O
W83877F WINBOND I/O
W83877TD I/O chip disk drive adapter
相關代理商/技術參數
參數描述
W83877ATD 制造商:WINBOND 制造商全稱:Winbond 功能描述:enhanced version from Winbonds most popular I/O chip W83877F
W83877ATF 制造商:WINBOND 制造商全稱:Winbond 功能描述:enhanced version from Winbonds most popular I/O chip W83877F
W83877F 制造商:WINBOND 制造商全稱:Winbond 功能描述:WINBOND I/O
W83877TD 制造商:WINBOND 制造商全稱:Winbond 功能描述:WINBOND I/O
W83877TF 制造商:WINBOND 制造商全稱:Winbond 功能描述:WINBOND I/O
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