ADM7008
Function Description
3.3.2 Dual Color LED
When Dual Color LED is programmed (DUALLED is set to high during power on reset),
all ports LED will be off during power on reset (Output high on LNKACT and LDSPD
and output recommend value on DUPCOL). After power on reset, all LEDs will be on
for 1 seconds to test 10M mode LNKACT/LDSPD connection and on for another 1
second to test 100M mode LNKACT/LDSPD wire connection. This period allow
manufacture operator to check whether the LED wire connection on PCB board is correct
or not.
After LED self-test, Table 3-9 and Table 3-10 show the On/Off polarity according to
different speed detected by ADM7008. DUPCOL is always set to single color mode
display no matter the value of DUALLED is.
SPEED
10M
100M
LDSPD
0
1
1
LINK FAIL
Table 3-9 Speed LED Display
Link/Activity
SPEED
Link
LOW
HIGH
Activity
100M LINK UP
10M LINK_UP
LINK FAIL
Blink (HIGH) When RX/TX
Blink (LOW) When RX/TX
HIGH All the Time
HIGH All the Time
Table 3-10 Activity/Link LED Display
Cable Length LED display mode controlled by register 19 will be disabled when dual
color mode is selected, by not displaying cable length, instead, ADM7008 display LED
status by default setting, i.e., LNKACT for Link/Activity LED, DUPCOL for
duplex/collision display and LDSPD for speed indication.
Refer to Table 3-7 for dual color blinking time.
3.3.3 Serial Output LED Status
Internal LED status will be streamed output through two pins – LED_DATA and
LED_CLK, where LED_DATA is used to indicate internal 8 port LED status and
synchronous to LED_CLK. Serial LED output sequence is programmed through
DUALLED during power on reset. RSMODE1 also affects the sequence of LED_DATA
and will be described as follows.
ADMtek Inc.
3-23
ETC [ ETC ]
