at7601fg AME, Inc., at7601fg Datasheet - Page 6

• Manufacturer Part Number: at7601fg
• Description: Printer Port Controller
• Manufacturer: AME, Inc.

6
AT7601F
5- 2- 1 Printer Status Port Address Offset = 01H
The Status Port is located at an offset of '01H' from the base address. The contents of this register are
Bit 7 BUSY# (BUSY)
This signal is active during data entry, when the printer is off-line during printing, when the print head is
changing position, or during an error state. When this signal is active, the printer is busy and cannot
accept data. This bit is the inversion value of the Busy input pin.
Bit 6 ACK# (ACKNOWLEDGE)
The level on the ACK# input is read by the CPU as bit 6 of the Printer Status Register. A logic 0 means
that the printer has received a character and can now accept another. A logic 1 means that it is still
processing the last character or has not received the data.
Bit 5 PE (PAPER END)
The level on the PE input is read by the CPU as bit 5 of the Printer Status Register. A logic 1 indicates a
paper end; a logic 0 indicates the presence of paper.
Bit 4 SLCT (PRINTER SELECTED STATUS)
The level on the SLCT input is read by the CPU as bit 4 of the Printer Status Register. A logic 1 means
the printer is on line; a logic 0 means it is not selected.
Bit 3 ERR# (ERROR)
The level on the Error# input is read by the CPU as bit 3 of the Printer Status Register. A logic 0 means
an error has been detected; a logic 1 means no error has been detected.
Bits 1, 2: are not implemented as register bits, during a read of the Printer Status Register these bits are
Logic High.
latched for the duration of an IOR# read cycle. The bits of the Status Port are defined as follows:
AME, Inc.
7
6
5
4
3
2
1
1
1
Printer Port Cotroller
0
ERROR
SLCT
PE
BUSY
TMOUT
ACK
Rev. B.02