Modul de lucru 'compatibil' - SPP (standard parallel port)
: implementeaza exact protocolul Centronics cel vechi, cu semnificatia cunoscuta a pinilor cuplei si mecanismele handshake obisnuite de acum. Evident este unidirectional, de la calculator catre imprimanta (sau alt periferic prost). O idee (mai veche ) de iutire a transferului pe acest port este modul 'Fast Centronics' sau modul FIFO (sau SPP+). Este tot unidirectional (cum altfel) si in conditiile unui controller ce stie asta, permite generarea tuturor semnalelor de handshake din hardware-ul portului paralel. Nu este standardizat si permite o rata de transfer de maxim 500kO/s -totusi de 10x mai mare. Daca nu am o imprimanta cu modurile 1284, acesta este singurul ajutor.
|
PIN |
direcTIE |
cOMPATIBIL |
NIBBLE |
BYTE |
EPP |
ECP |
|
O |
nStrobe |
HostClk |
HostClk |
HostClk |
nWrite |
|
|
B |
Data 1 (LSB) |
AD1 |
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|
B |
Data 2 23123w2218x |
AD2 |
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|
B |
Data 3 |
AD3 |
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|
B |
Data 4 |
AD4 |
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B |
Data 5 |
AD5 |
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|
B |
Data 6 |
AD6 |
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|
B |
Data 7 |
AD7 |
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|
B |
Data 8(MSB) |
AD8 |
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|
I |
nAck |
PtrClk |
PtrClk |
PeriphClk |
Intr |
|
|
I |
Busy |
PtrBusy |
PtrBusy |
PeriphAck |
nWait |
|
|
I |
PEnd |
AckDReq |
AckDReq |
nAckRev |
UserDef1 |
|
|
I |
Sel |
XFlag |
XFlag |
XFlag |
UserDef3 |
|
|
O |
nAuto |
HostBusy |
HostBusy |
HostAck |
nDataStrb |
|
|
Not Defined |
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|
Logic Ground |
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|
Chassis Ground |
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|
I |
Peripheral Logic High |
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|
Signal Ground nStrobe |
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|
Signal Ground D1 |
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Signal Ground D2 |
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Signal Ground D3 |
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Signal Ground D4 |
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Signal Ground D5 |
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Signal Ground D6 |
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Signal Ground D7 |
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Signal Ground D8 |
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Signal Ground Pend, Sel, nAck |
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Signal Ground Busy, nErr |
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Signal Ground nAuto, nSelIn, nInit |
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|
O |
nInit |
nInit |
nInit |
nRevReq |
nInit |
|
|
I |
nErr |
nDataAvail |
nDataAvail |
nPeriphReq |
UserDef2 |
|
|
NotDefined |
NotDefined |
NotDefined |
NotDefined |
NotDefined |
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|
NotDefined |
NotDefined |
NotDefined |
NotDefined |
NotDefined |
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|
NotDefined |
NotDefined |
NotDefined |
NotDefined |
NotDefined |
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|
O |
nSelIn |
1284Active |
1284Active |
1284Active |
nAddStrb |
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