CS89712 Datasheet, PDF (46/170 Pages) Cirrus Logic – HIGH-PERFORMANCE, LOW-POWER SYSTEM-ON-CHIP WITH 10BASE-T ETHERNET CONTROLLER

CS89712
Command
Read Register
Write Register
Erase Register
Erase/Write Enable
Erase/Write Disable
Erase-All Registers
Write-All Register
Opcode
(bits 9,8)
1,0
0,1
1.1
0,0
0,0
0,0
0,0
0,0
0,0
0,0
EEPROM Address
(bits 7 to 0)
word address
word address
word address
XX11-XXXX
11XX-XXXX
XX00-XXXX
00XX-XXXX
XX10-XXXX
10XX-XXXX
XX01-XXXX
01XX-XXXX
Data
yes
yes
no
no
no
no
no
no
no
yes
yes
EEPROM Type
all
all
all
‘CS46, ‘C46
‘CS56, ‘C56, ‘CS66, ‘C66
‘CS46, ‘C46
‘CS56, ‘C56, ‘CS66, ‘C66
‘CS46, ‘C46
‘CS56, ‘C56, ‘CS66, ‘C66
‘CS46, ‘C46
‘CS56, ‘C56, ‘CS66, ‘C66
Table 26. EEPROM Commands
Execution
Time
25 µs
10 ms
10 ms
9 µs
9 µs
9 µs
9 µs
10 ms
9 µs
10 ms
10 ms
2.24.4 Writing and Erasing the EEPROM
To write data to the EEPROM, the software must
execute the following series of commands:
1) Issue an Erase/Write Enable command.
2) Load the data into the EEPROM Data register.
3) Issue a Write command.
4) Issue an Erase/Write Disable command.
During the Erase command, the Ethernet port
writes FFh to the specified EEPROM location.
During the Erase-All command, the Ethernet port
writes FFh to all locations.
2.25 Ethernet LEDs
The Ethernet port provides three output pins that
can be used to control LEDs or external logic.
2.25.1 LANLED
LANLED goes low whenever the Ethernet port
transmits or receives a frame, or when it detects a
collision. LANLED remains low until there has
been no activity for 6 ms (i.e. each transmission, re-
ception, or collision produces a pulse lasting a min-
imum of 6 ms).
2.25.2 LINKLED or HC0
LINKLED or HC0 can be controlled by either the
Ethernet port or the software. When controlled by
the Ethernet port, LINKLED is low whenever the
Ethernet port receives valid 10BASE-T link pulses.
To configure this pin for software control, the
HC0E bit (SelfCTL register, Bit C) must be clear.
When controlled by the software, LINKLED is low
when the HCB0 bit (SelfCTL register, Bit E) is set.
To configure it for software control, the HC0E bit
must be set. Table 27 summarizes this operation.
HC0E
(Bit C)
0
1
1
HCB0
(Bit E)
Pin Function
N/A _{Pin configured as LINKLED:}
Output is low when valid
10BASE-T link pulses are
detected. Output is high if valid
link pulses are not detected
0 _{Pin configured as HC0:}
Output is high
1 _{Pin configured as HC0:}
Output is low
Table 27. LINKLED/HC0 Pin Operation
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