
FingerTIP
Infineon Technologies
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FTF 1100 MF1 V2.0 databook 3.3 (05.00)
3 The Parallel Interface EPP 1.9
This chapter describes the parallel interface of the FingerTIP and how to read out an
image, change the dynamics and set sleep mode. First the data transfer protocol, electrical
and timing parameters of the sensor's EPP mode, which is compatible to the IEEE 1284
standard, is described. Next the readout procedure will be explained using a block
diagram. Finally, the pinout of the sensor's parallel port is shown.
For further information for design-in the sensor, please refer to the Design-In Guideline /2/.
3.1 Basic Information on the Parallel Interface
The FingerTIP offers an EPP 1.9 compatible parallel interface according to the IEEE
1284 standard. The IEEE 1284 defines five different data transfer modes: Standard Mode
(SPP), Nibble Mode, Byte Mode, Extended Capabilities Port Mode (ECP) and Enhanced
Parallel Port Mode (EPP). Only the ECP and EPP modes use a hardware-implemented
handshake for data transfer. This leads to high data rates of at least 1MByte/s. The
FingerTIP has an EPP 1.9 compatible interface which is easy to implement on the PC
side and which can easily be emulated by a microcontroller/processor. Please note that
the older version EPP 1.7, which does not meet the IEEE 1284 standard, is not supported
by the FingerTIP.
If not already done, the EPP 1.9 mode can be enabled on the PC by entering the BIOS
setup menu or by using a BIOS setup utility program. The FingerTIP cannot be used on
printer ports which do not support EPP 1.9.
The sensor represents a level-two EPP device, which is designed for high data rates
according to IEEE 1284.
The IEEE 1284 standard specifies four different modes for EPP 1.9: Read data, write data,
write address and read address. The FingerTIP only supports the read data cycle.
Therefore the sensor uses only two handshake lines (nDataStrb/REQUEST and
nWait/READY) and 8 data lines. An additional line (nReset/RESET) is used for resetting
the sensor's pixel pointer, selecting the sleep mode and for changing the dynamics. The
following sections describe the timing, signal definition and protocol.
More background information on the EPP parallel port protocol can be found, for example,
in the book Parallel Port Complete /3/