CS8900-IQ View Datasheet(PDF) - Cirrus Logic
Part Name
Description
MFG CO.
CS8900-IQ Datasheet PDF : 138 Pages
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CS8900A
Crystal LAN™ ISA Ethernet Controller
exit from this mode, the SLEEP pin must be driven
high. Upon exit, the CS8900A performs a complete
reset, and then goes through a normal initialization
procedure.
3.7.3 Software Suspend
Software (SW) Suspend mode can be used to con-
serve power in applications, like adapter cards, that
do not have power management circuitry available.
During this mode, all internal circuits are shut off
except the I/O Base Address register (PacketPage
base + 0020h) and the SelfCTL register (Register
15).
To enter SW Suspend mode, the host must set the
SWSuspend bit (Register 15, SelfCTL, bit 8). To
exit SW Suspend, the host must write to the
CS8900A’s assigned I/O space (the Write is only
used to wake the CS8900A, the Write itself is ig-
nored). Upon exit, the CS8900A performs a com-
plete reset, and then goes through a normal
initialization procedure.
Any hardware reset takes the chip out of any sleep
mode.
Table 8 summarizes the operation of the three low-
power modes.
CS8900A Configuration
CS8900A Operation
SLEEP HWStandbyE HWSleepE SWSuspend
(Pin 77) (SelfCTL, Bit A) (SelfCTL, Bit 9) (SelfCTL, Bit 8) Link Activity
Low
1
1
N/A
Not Present HW Standby mode: 10BASE-T
receiver listens for link activity
Low
1
1
N/A
Present HW Standby mode: LANLED low
Low
0
1
N/A
N/A
HW Suspend mode
Low to
N/A
1
High
0
N/A
CS8900A resets and goes through
initialization
High
N/A
N/A
0
N/A
Not in low-power mode
High
N/A
N/A
N/A
SW Suspend mode
Low
N/A
0
1
N/A
SW Suspend mode
Low
N/A
0
0
N/A
Not in low-power mode
Notes: 1. Both HW and HW Suspend take precedence over SW Suspend.
Table 8. Low-Power Mode Operation
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