CS8900-CQ3 Cirrus Logic, CS8900-CQ3 Datasheet - Page 27

• Manufacturer Part Number: CS8900-CQ3
• Description: Crystal LAN ISA Ethernet Controller
• Manufacturer: Cirrus Logic

DS271PP3
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).
Notes: 1. Both HW and HW Suspend take precedence over SW Suspend.
CS8900A
Crystal LAN™ ISA Ethernet Controller
(Pin 77)
SLEEP
Low to
High
High
High
Low
Low
Low
Low
Low
(SelfCTL, Bit A)
HWStandbyE
N/A
N/A
N/A
N/A
N/A
1
1
0
CS8900A Configuration
(SelfCTL, Bit 9)
HWSleepE
N/A
N/A
CIRRUS LOGIC PRODUCT DATA SHEET
1
1
1
1
0
0
Table 8. Low-Power Mode Operation
(SelfCTL, Bit 8) Link Activity
SWSuspend
N/A
N/A
N/A
0
0
1
0
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.
Not Present HW Standby mode: 10BASE-T
Present
N/A
N/A
N/A
N/A
N/A
N/A
receiver listens for link activity
HW Standby mode: LANLED low
HW Suspend mode
CS8900A resets and goes through
initialization
Not in low-power mode
SW Suspend mode
SW Suspend mode
Not in low-power mode
CS8900A Operation
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