at7601fg AME, Inc., at7601fg Datasheet - Page 7

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

Rev. B.02
AT7601F
5-2-2 Printer Control Port
Bit 0 TMout: TIME OUT
The bit is valid in EPP mode only and indicates that a 10 uSec time out has occurred on the
EPP bus. A logic 0 means that no time out error has occurred; a logic 1 means that a time out error has
been detected. This bit is cleared by a RESET. Writing a one to this bit clears
the time out status bit. On a write, this bit is self clearing and does not require a write of a zero. Writing a
zero to this bit has no effect.
Bit 6 and 7 These tow bits are Logic High during a read, and cannot be written.
Bit 5 PDIR (PARALLEL DIRECTION CONTROL)
Parallel Direction Control is not valid in printer mode. In printer mode, the direction is always out regardless
of the state of this bit. In bi-directional, EPP or ECP mode, 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 IRQEn (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. An interrupt request is generated on the IRQ port by a positive going ACK# input.
When the IRQEn bit is programmed low the IRQ is disabled.
The Control Port is located at an offset of '02H" from the base address. The Control Register is initialized by
the RESET input, bits 0 to 5 only being affected; bits 6 and 7 are Logic High.
AME, Inc.
1
7
1
6
ADDRESS PORT = 02H
5
4
3
2
1
0
Printer Port Controller
STROBE
INIT
SLCT IN
IRQ ENABLE
DIR
AUTO FD
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