PIN DESIGNATIONS
Listed By Driver Type
A sustained tri-state signal is a low active signal that is
driven high for one clock period before it is left floating.
The following table describes the various types of out-
put drivers used in the Am79C978 controller. All IOL and
IOH values shown in the table apply to 3.3 V signaling.
TX is a differential output driver. Its characteristics and
those of XTAL2 output are described in the DC CHAR-
ACTERISTICS section.
Driver Name
Type
IOL (mA)
IOH (mA)
Load (pF)
50
LED
O6
LED
12
6
0.4
0.4
NA
2
Totem Pole
Open Drain
Tri-State
Tri-State
50
OD6
TS3
TS6
STS6
6
50
3
50
6
2
50
Sustained Tri-State
Tri-State
6
2
50
OMII1
OMII2
TSMII
4
4
50
Tri-State
4
4
390
470
Tri-State
4
4
For typical 5 V DC characteristics, please refer to DC
Characteristics Over Commercial Operating Ranges
section.
24
Am79C978
AMD [ AMD ]
