Part 2: Product SpecificationsBJC-2000BJC-2000
ECP mode
In ECP mode, the printer transfers data at once in 8-bit units allowing faster data
transmission and reception. This mode is suitable for large data transfers such as
for scanners.
After the computer responds to the Low Reverse Request signal, the AckReverse
signal goes Low and the data bus direction switches from the forward data
transmission phase (host computer to printer) to the reverse data transmission
phase (printer to host computer).
During the reverse data transmission phase, the HostAck signal confirms that the
PeriphClk is High before it goes Low. HostAck signal goes Low when the printer is
ready to receive data from the host computer. The host computer raises the HostAck
signal after it receives the data.
During reverse data transmission, a high PeriphAck signal represents "data" whereas
a Low signal represents a "command."
1284 Active
AckReverse
Data(1~ 8)
00010000Byte0Byte1
HostAck
nCmdnCmd
HostClk
PeriphClk
PeriphAck
PeriphReq
Xflag
ECP modeSupport
TPTP
TP
TP
TP:minimumsetup
Figure 2-12 Timing Chart (ECP Mode)
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ACEC
