Sharp UP-5300, Service Manual

Page: 63 / 123

Name Number Type Description
DRV2
ADRxJ
TR2
ECPEN1
94 I
O24
O24
I
Drive 2. In PS/2 mode, this input indicates whether a second drive is connected: this signal should be
low if a second drive is connected. This status is reflected in a read of Status Register A.
Optional I/O port address decode output. Defaults to tri-state after power-up.
This pin has 30
µ
A internal pull-up. This interrupt from the parallel port enabled/disabled via bit 4 of the
Parallel Port Control Register. Refer to Configuration Registers CRC for more information.
Enhanced parallel port mode select. Read and latched during reset active.
SLCTINJ 73 O20 Printer select input. This active low signal selects the printer. This is the complement of bit 3 of the
Printer Control Register.
INITJ 74 O20 Initiate Output. This active low signal is bit 2 of the printer control register. This is used to initiate the
printer when low.
AUTOFDJ 76 O20 Autofeed Output. This active low output causes the printer to automatically feed one line after each
line is printed. This signal is the complement of bit 1 of the Printer Control Register.
STROBEJ 77 O20 Strobe Output. This active low pulse is used to strobe the printer data into the printer. This output
signal is the complement of bit 0 of the Printer Control Register.
BUSY 61 I Busy. This signal indicates the status of the printer. A high indicates the printer is busy and not ready to
receive new data. Bit 7 of the Printer Status Register is the complement of the BUSY input.
ACKJ 62 I Acknowledge. This active low output from the printer indicates it has received the data and is ready to
accept new data. Bit 6 of the Printer Status Register reads the ACKJ input.
PE 60 I Paper End. This signal indicates that the printer is out of paper. Bit 5 of the Printer Status Register
reads the PE input.
LCT 59 I Printer Selected Status. This active high output from the printer indicates that it has power on. Bit 4 of
the Printer Status Register reads the SLCT input.
ERRORJ 75 I Error. This active low signal indicates an error condition at the printer.
PD0-PD7 71-68, 66-63 I/O20 Port Data. This bi-directional parallel data bus is used to transfer information between CPU and
peripherals.
IOCHRDY 100 OD24 IOCHRDY. In EPP mode, this pin is pulled low to extend the read/write command.
DRQA/
SICF1 23 O24
I DMA Request. Alternate DMA request output for parallel port. Refer to CR5 bit 3.
Primary Serial Configuration 1. Read and latched during reset active to select the address of the
Primary Serial Port.
PINTR3/
SICF0
24 O24
I
Parallel Port Interrupt Request. Alternate IRQ output from Parallel Port. Refer to CR0 bit 4 for more
information.
Primary Serial Configuration 0. Read and latched during reset active to define the address of the
Primary Serial Port.
IRTX2
CFG2 25 O4
I Alternate IR Transmit output.
This pin is read and latched during reset active to select the hardware configuration port. This pin is
internal pull high. If it is low during reset, the hardware configuration port defaults to 3F1h. If it is high
during reset, the hardware configuration port defaults to 398h.
IRRX2
FACF 26 I Alternate IR Receive input.
Floppy Disk Address Control. This signal is read and latched during reset active.
UR2IRQB 22 O24 Serial Port Interrupt Request. Alternate IRQ output from UART2, refer to CR0 bit 5.
Miscellaneous
PWRGD 58 I Power Good. This input signal indicates that the power is valid. For device operation, PWRGD must be
active.
X1/CLK1 20 ICLK Clock 1. This external connection for a parallel resonant 24 MHz crystal. ACMOS compatible oscillator
is required if crystal is not used.
X2/CLK2 21 OCLK Clock 2. This is a 24 MHz crystal. If an external clock is used, this pin should not be connected. This
pin should not be used to drive any other drivers.
Vcc 15, 72 P Power. +5 Volt supply pin.
Vss 6, 47, 67, 95 P Ground pins.
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