Panasonic KX-HCM280, Service Manual

Page: 85 / 182

Pin No. Pin Name Description
43 nROM This pin is sampled at the end of RESET. For
ISA operation this pin is left open end it is
used as a ROM chip select output that goes
active when nMEMR is low and the address
bus contains a valid ROM address.
76-78, 80-87 AQ0-10 Input address lines 0 through 10.
89-97 A11-19 Input address lines 11 through 19.
2 AEN ISA - Address enable input. Used as an
address qualifier. Address decoding is only
enabled when AEN is low.
74 nSBHE ISA - Byte High Enable input. Asserted (low) by
the system to indicate a data transfer on the
upper data byte.
3 IOCHRDY ISA - Output. Optionally used by the LAN91C93
to extend host cycles.
5-8, 10-13, 57-60,
62-65
D0-15 Bi-directional. 16 bit data bus used to access
the LAN91C93 internal registers. The data bus
has weak internal pullups. Supports direct
connection to the system bus without external
buffering.
15 RESET Input. Active high Reset. This input is not
considered active unless it is active for at
least 100ns to filter narrow glitches.
68 INTR ISA - Active high interrupt signal.
72 nIOCS16 ISA - Active low output asserted in 16 bit mode
when AEN is low and A4-A15 decode to the
LAN91C93 address programmed into the high
byte of the Base Address Register.
99 nIORD ISA, - Input. Active low read strobe used to
access the LAN91C93 IO space.
100 nIOWR ISA, - Input. Active low write strobe used to
access the LAN91C93 IO space.
1 nMEMR ISA - Active low signal used by the host
processor to read from the external ROM.
55 EESK Output. 4 usec clock used to shift data in and
out of a serial EEPROM.
54 EECS Output. Serial EEPROM chip select.
52 EEDO Output. Connected to the DI input of the serial
EEPROM.
53 EEDI Input. Connected to the DO output of the serial
EEPROM.
46, 47 IOS0-1 Input. External switches can be connected to
these lines to select between predefined
EEPROM configurations. The values of these
pins are readable.
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