
8019AS.doc 
2001-05-10
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SPECIFICATION  
RTL8019AS  
21
BROM size 
16K 
32K 
64K 
BA14      BA15 
high        high 
SA14       high 
 SA14       SA15 
CONFIG3: RTL8019AS Configuration Register 3 (06H; Type=R except Bit[2:1]=R/W)   
Bit 
Symbol 
7 
PNP 
This bit is negligible in jumper mode. In jumperless mode it, when set, indicates the 
RTL8019AS is operating in Plug and Play mode. This bit is set when the PNP pin is 
high or the PNP bit in 9346 is set in jumperless mode. 
6 
FUDUP 
When this bit is set, RTL8019AS is set to the full-duplex mode which enables 
simultaneously transmission and reception on the twisted-pair link to a full-duplex 
Ethernet switching hub.  This feature not only increases the channel bandwidth from 
10 to 20 Mbps but also avoids the performance degrading problem due to the channel 
contention characteristics of the Ethernet CSMA/CD protocol. 
5-4 
LEDS1-0 
These two bits select the outputs to LED2-0 pins. 
LEDS0 
0 
1 
LEDS1 
0 
1 
Please refer to section 6.5 for the behavior of LEDs. 
The MCSB signal is defined to put the local buffer SRAM into standby mode while 
DMA is not in progress and thus save powers. 
3 
- 
Reserved. 
Must not
 write a 1 to this bit.  
2 
SLEEP 
This bit, when set, puts RTL8019AS into sleep mode.  
In sleep mode, all LED signals (P.S. MCSB is not an LED signal) except LEDBNC 
are forced high to turn off the LEDs. The RTL8019AS still handles the network 
transmission and reception like in normal mode. The LEDBNC is not affected by this 
bit.  
This bit's power-up initial value is 0 and can be modified by software when 
EEM1=EEM0=1. 
1 
PWRDN 
This bit , when set, puts RTL8019AS into power down mode.  
RTL8019AS supports two kinds of power down modes, which is selected by the 
contents of the HLTCLK register:  
(1) mode 1: power down with clock running  
(2) mode 2: power down with clock halted 
In both power down modes, the RTL8019AS's serial network interface and transceiver 
are turned off. All network activities are ignored.  
All LED signals except LEDBNC are forced high. The LEDBNC is forced low to 
disable the DC convertor for coaxial transceiver.  
In power down mode2, the RTL8019AS stops its internal clock for minimal power 
consumption. Registers except HLTCLK are typically not accessible in this mode. 
This bit's initial value comes from 9346 and can be modified if EEM1=EEM0=1 in 
9346CR register.  
Description 
LED0 Pin 
LED_COL 
LED_LINK 
LED1 Pin 
LED_RX 
LED_CRS 
LED2 Pin 
LED_TX 
MCSB