cs89712 Cirrus Logic, Inc., cs89712 Datasheet - Page 46

• Manufacturer Part Number: cs89712
• Description: High-performance, Low-power System-on-chip With 10base-t Ethernet Controller
• Manufacturer: Cirrus Logic, Inc.

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).
46
Erase/Write Disable
Erase/Write Enable
Erase-All Registers
Write-All Register
Erase Register
Read Register
Write Register
Command
(bits 9,8)
Opcode
1,0
0,1
0,0
0,0
1.1
0,0
0,0
0,0
0,0
0,0
EEPROM Address
word address
word address
word address
Table 26. EEPROM Commands
11XX-XXXX
XX00-XXXX
00XX-XXXX
XX10-XXXX
10XX-XXXX
XX01-XXXX
01XX-XXXX
(bits 7 to 0)
XX11-XXXX
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.
Data
(Bit C)
HC0E
yes
yes
yes
yes
no
no
no
no
no
no
no
0
1
1
Table 27. LINKLED/HC0 Pin Operation
‘CS56, ‘C56, ‘CS66, ‘C66
‘CS56, ‘C56, ‘CS66, ‘C66
‘CS56, ‘C56, ‘CS66, ‘C66
‘CS56, ‘C56, ‘CS66, ‘C66
(Bit E)
HCB0
N/A
Table 27
0
1
EEPROM Type
‘CS46, ‘C46
‘CS46, ‘C46
‘CS46, ‘C46
‘CS46, ‘C46
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
Pin configured as HC0:
Output is high
Pin configured as HC0:
Output is low
all
all
all
summarizes this operation.
Pin Function
CS89712
Execution
DS502PP2
10 ms
10 ms
10 ms
10 ms
10 ms
25 µs
Time
9 µs
9 µs
9 µs
9 µs
9 µs