at7601fg AME, Inc., at7601fg Datasheet - Page 14

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

14
AT7601F
5-3-1.2 Device Status Register (DSR)
5-3-1.3 Device Control Register (DCR)
This bit is inverted and output onto the AFD# output. A logic 1 causes the printer to generate a line feed
The Status Port is located at an offset of '01H'from the base address. Bits 0-2 are not implemented as
register bits; during a read of the Printer Status Register these bits are a low level. The bits of the Status
Port are defined as follows:
Bit 0-2: the Status Port is located at an offset of '01H'from the base address. Bits 0-2 are not imple-
mented as register bits; during a read of the Printer Status Register these bits are a low level.
Bit 3 Fault# : The level on the Fault# input is read by the CPU as bit 3 of the Device Status Register.
Bit 4 SLCT: The level on the Select input is read by the CPU as bit 4 of the Device Status Register.
Bit 5 PError: The level on the PError input is read by the CPU as bit 5 of the Device Status Register.
Printer Status Register.
Bit 6 ACK#: The level on the ACK# input is read by the CPU as bit 6 of the Device Status Register.
Bit 7 BUSY#: This complement of the level on the BUSY input is read by the CPU as bit 7 of the Device
Status Register.
The Control Register is located at an offset of '02H'from the base address. The Control Register is
initialized to zero by the RESET input, bits 0 to 5 only being affected; bits 6 and 7 are hard wired low.
Bit 6 and 7 during a read are a low level, and cannot be written.
Bit 5 PDIR:
If mode=000 or mode=010, this bit has no effect and the direction is always out regardless of the state of
this bit. In all other modes, Direction is valid and a logic 0 means that the printer port is in output mode
(write); a logic 1 means that the printer port is in input mode (read).
Bit 4 AckIntEn-INTERRUPT REQUEST ENABLE: The interrupt request enable bit when set to a high
level may be used to enable interrupt requests from the Parallel Port to the CPU due to a low to high
transition on the ACK# input. Refer to the description of the interrupt under Operation, Interrupts.
Bit 3 SLIN: This bit is inverted and output onto the SLIN# output. A logic 1 on this bit selects the printer;
a logic 0 means the printer is not selected.
Bit 2 INIT# (INITIATE OUTPUT):
This bit is output onto the INIT# output without inversion.
Bit 1 AFD (AUTOFEED):
after each line is printed. A logic 0 means no autofeed.
Bit 0 STB (STROBE):
This bit is inverted and output onto the STROBE# output.
AME, Inc.
Printer Port Cotroller
Rev. B.02