Index DW9937S, Service Manual

Page: 10 / 112

SLLS423D – JUNE 2000 – REVISED SEPTEMBER 2002
POST OFFICE BOX 655303
•
DALLAS, TEXAS 75265
description (continued)
required for normal network operation regardless of the state of the PHY-LLC interface. When the interface is
in the reset or disabled state and LPS is again observed active, the PHY initializes the interface and returns it
to normal operation.
When the PHY-LLC interface is in the low-power disabled state, the TSB41AB1 automatically enters a
low-power mode if the port is inactive (disconnected, disabled, or suspended). In this low-power mode, the
TSB41AB1 disables its internal clock generators and also disables various voltage and current reference
circuits depending on the state of the port (some reference circuitry must remain active in order to detect new
cable connections, disconnections, or incoming TPBIAS, for example). The lowest power consumption (the
ultralow-power sleep mode) is attained when the port is either disconnected, or disabled with the port interrupt
enable bit cleared. The TSB41AB1 exits the low-power mode when the LPS input is asserted high or when a
port event occurs which requires that the TSB41AB1 become active in order to respond to the event or to notify
the LLC of the event (for example, incoming bias is detected on a suspended port, a disconnection is detected
on a suspended port, a new connection is detected on a nondisabled port, etc.). The SYSCLK output becomes
active (and the PHY-LLC interface is initialized and becomes operative) within 7.3 ms after LPS is asserted high
when the TSB41AB1 is in the low-power mode.
The PHY uses the C/LKON terminal to notify the LLC to power up and become active. When activated, the
C/LKON signal is a square wave of approximately 163-ns period. The PHY activates the C/LKON output when
the LLC is inactive and a wake-up event occurs. The LLC is considered inactive when either the LPS input is
inactive, as described above, or the LCtrl bit is cleared to 0. A wake-up event occurs when a link-on PHY packet
addressed to this node is received, or when a PHY interrupt occurs. The PHY deasserts the C/LKON output
when the LLC becomes active (both LPS active and the LCtrl bit set to 1). The PHY also deasserts the C/LKON
output when a bus reset occurs unless a PHY interrupt condition exists which would otherwise cause C/LKON
to be active.
PHP package terminal diagram
14 15
AGND
AV
DD
R1
R0
AGND
TPBIAS
TPA+
TPA–
TPB+
TPB–
AGND
AV
DD
36
35
34
33
32
31
30
29
28
27
26
25
16
1
2
3
4
5
6
7
8
9
10
11
12
SYSCLK
CTL0
CTL1
D0
D1
D2
D3
D4
D5
D6
D7
PD
17 18 19 20
47 46 45 44 43 48 42 40 39 38 41
21 22 23 24
37
13
PHP PACKAGE
(TOP VIEW)
TSB41AB1
PLLGND PLL
V
FIL
TER1
FIL
TER0
LREQ DGND DGND DV
TESTM
SE
SM
C/LKON
PC1 PC2
ISO
CPS
DV
RESET XO XI
DGND
LPS
PC0
DD
DV
DD
DD
DD
8