
8019AS.doc 
2001-05-10
·R¥bééa¥÷|3--¤¥q
SPECIFICATION  
RTL8019AS  
6
4. PIN DESCRIPTIONS
4.1.  Power Pins 
No. 
Name 
Type 
Description 
6, 17, 47, 57, 70, 
89 
VDD 
P 
+5V DC power 
14, 28, 44, 52, 
83, 86 
GND 
P 
Ground 
4.2.  ISA Bus Interface Pins
No. 
Name 
Type 
Descriptions 
34 
AEN 
I 
Address Enable. This ISA signal must be low for a valid I/O 
command. 
97-100, 1-4 
INT7-0 
O 
Interrupt request lines which are mapped to IRQ15, IRQ12, 
IRQ11, IRQ10, IRQ5, IRQ4, IRQ3, IRQ2/9 respectively. 
Only one line is selected to reflect the interrupt requests at 
one time. All other lines are tri-stated. The RTL8019AS also 
uses these pins as inputs to monitor the actual state of the 
corresponding interrupt lines on ISA bus. The result is 
recorded in the INTR register, which may be used by software 
to detect interrupt conflict. 
35 
IOCHRDY 
O 
This ISA signal is driven low to insert wait cycles to current 
host read/write command. 
96 
IOCS16B 
[SLOT16] 
O 
Upon power-on reset, this pin acts as an input named 
SLOT16 to detect whether a 16-bit or 8-bit slot is in use. To 
do this, it is connected to a pull-down resistor (about 27KW) 
externally. At the falling edge of RSTDRV, the RTL8019AS 
senses this pin's state. If it is sensed high, the adapter is 
thought to be placed on a 16-bit slot where this pin is 
connected to the host's IOCS16B pin, which is typically 
pulled up by a 300W resistor on the mother board. If it is 
sensed low, the adapter is thought to be placed on an 8-bit 
slot where this pin is merely pulled low by the 27KW resistor. 
After having latched the input state, this pin is switched as 
the IOCS16B signal which is an open-drain output and is 
driven low during a 16-bit host data transfer. It is decoded 
from AEN and SA9-0. 
29 
IORB 
I 
Host I/O read command. 
30 
IOWB 
I 
Host I/O write command. 
33 
RSTDRV 
I 
High active hardware reset signal from the ISA bus. Pulses 
with high level less than 800ns are ignored. 
27-18, 16-
15, 13-7, 5 
SA19-0 
I 
Host address bus. SA10 is added to implement the fully 
decode of PnP ports, address 279h and A79h. In RTL8019, 
SA10 is not decoded. In RTL8019AS, SA10 should be 0 for a 
valid access to PnP ports. 
87-88, 90-
95, 43-36 
SD15-0 
I/O 
Host data bus.