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參數資料
型號： W83977CTF
廠商： WINBOND ELECTRONICS CORP
英文描述： Multi-Function I/O Port Controller(用于個人計算機的多功能輸入/輸出口控制器)
中文描述： 多功能I / O端口控制器（用于個人計算機的多功能輸入/輸出口控制器）
文件頁數： 86/161頁
文件大?。?/td> 1530K
代理商： W83977CTF
W83977EF/ CTF
PRELIMINARY
Publication Release Date: March 1999
-77 -
Revision A1
5.3.15 DMA Transfers
DMA transfers are always to or from the ecpDFifo, tFifo, or CFifo. The DMA uses the standard PC
DMA services. The ECP requests DMA transfers from the host by activating the PDRQ pin. The DMA
will empty or fill the FIFO using the appropriate direction and mode. When the terminal count in the
DMA controller is reached, an interrupt is generated and serviceIntr is asserted, which will disable the
DMA.
5.3.16 Programmed I/O (NON-DMA) Mode
The ECP or parallel port FIFOs can also be operated using interrupt driven programmed I/O.
Programmed I/O transfers are to the ecpDFifo at 400H and ecpAFifo at 000H or from the ecpDFifo
located at 400H, or to/from the tFifo at 400H. The host must set the direction, state, dmaEn = 0 and
serviceIntr = 0 in the programmed I/O transfers.
The ECP requests programmed I/O transfers from the host by activating the IRQ pin. The
programmed I/O will empty or fill the FIFO using the appropriate direction and mode.
5.4
In this mode, the W83977EF/CTF changes the printer interface pins to FDC input/output pins,
allowing the user to install a second floppy disk drive (FDD B) through the DB-25 printer connector.
The pin assignments for the FDC input/output pins are shown in Table 5-1.
After the printer interface is set to EXTFDD mode, the following occur:
(1) Pins MOB# and DSB# will be forced to inactive state.
(2) PinsDSKCHG#, RDATA#, WP#, TRAK0#, INDEX# will be logically ORed with pins PD4-PD0 to
serve as input signals to the FDC.
(3) Pins PD4-PD0 each will have an internal resistor of about 1K ohm to serve as pull-up resistor for
FDD open drain/collector output.
(4) If the parallel port is set to EXTFDD mode after the system has booted DOS or another operating
system, a warm reset is needed to enable the system to recognize the extension floppy drive.
Extension FDD Mode (EXTFDD)
5.5
In this mode, the W83977EF/CTF changes the printer interface pins to FDC input/output pins,
allowing the user to install two external floppy disk drives through the DB-25 printer connector to
replace internal floppy disk drives A and B. The pin assignments for the FDC input/output pins are
shown in Table5-1.
After the printer interface is set to EXTFDD mode, the following occur:
(1) Pins MOA#, DSA#, MOB#, and DSB# will be forced to inactive state.
(2) Pins DSKCHG#, RDATA#, WP#, TRAK0#, and INDEX# will be logically ORed with pins PD4-PD0
to serve as input signals to the FDC.
(3) Pins PD4-PD0 each will have an internal resistor of about 1K ohm to serve as pull-up resistor for
FDD open drain/collector output.
(4) If the parallel port is set to EXT2FDD mode after the system has booted DOS or another operating
system, a warm reset is needed to enable the system to recognize the extension floppy drive.
Extension 2FDD Mode (EXT2FDD)
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相關代理商/技術參數
參數描述
W83977CTF-AW 制造商:未知廠家 制造商全稱:未知廠家 功能描述:PERIPHERAL (MULTIFUNCTION) CONTROLLER
W83977CTF-PW 制造商:WINBOND 制造商全稱:Winbond 功能描述:WINBOND I/O
W83977EF 制造商:WINBOND 制造商全稱:Winbond 功能描述:WINBOND ISA I/O
W83977EF-AW 制造商:WINBOND 制造商全稱:Winbond 功能描述:WINBOND ISA I/O
W83977EF-PW 制造商:WINBOND 制造商全稱:Winbond 功能描述:WINBOND I/O
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