78Q8430-100CGT/F TERIDIAN, 78Q8430-100CGT/F Datasheet - Page 4

• Manufacturer Part Number: 78Q8430-100CGT/F
• Description: IC, ETHERNET TXRX, IEEE 802.3, LQFP-100
• Manufacturer: TERIDIAN

Specifications of 78Q8430-100CGT/F

• No. Of Ports: 2
• Ethernet Type: IEEE 802.3x, IEEE 802.3u, IEEE 802.3-2000
• Ic Interface Type: Host Bus, JTAG
• Supply Voltage Range: 0V To 3.3V
• Operating Temperature Range: 0°C To +70°C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Polarity Correction
The 78Q2123/78Q2133 are capable of either
automatic or manual polarity reversal for 10BASE-T
and auto-negotiation functions.
MR16.5 and MR16.4 control this feature.
default is automatic mode where MR16.5 is low and
MR16.4 indicates if the detection circuitry has
inverted the input signal. To enter manual mode,
MR16.5 should be set high and MR16.4 will then
control the signal polarity.
SQE TEST
The 78Q2123/78Q2133 support the Signal Quality
Error (SQE) function detailed in IEEE-802.3. At an
interval of 1µs after each negative transition of the
TXEN pin in 10BASE-T mode, the COL pin will go
high for a period of 1µs. SQE is not signalled during
transmission after collision is detected.
automatically disabled when repeater mode is
enabled.
register bit MR16.11.
Natural Loopback
When enabled, whenever the 78Q2123/78Q2133
are transmitting and not receiving on the twisted pair
media (10BASE-T Half Duplex mode), data on the
TXD3-0 pins are looped back onto the RXD3-0 pins.
During a collision, data from the RXI pins is routed to
the RXD3-0 pins. The natural loopback function is
enabled through register bit MR16.10. This feature
is off by default.
Repeater Mode
When
78Q2123/78Q2133 are placed in repeater mode. In
this mode, full duplex operation is prohibited, CRS
responds only to receive activity and, in 10BASE-T
mode, the SQE test function is disabled.
AUTO-NEGOTIATION
The 78Q2123/78Q2133 support the auto-negotiation
functions of Clause 28 of IEEE-802.3 for 10/100
Mbps operation over copper wiring. This function
can be enabled via register settings.
negotiation function defaults to ON and bit MR0.12
(ANEGEN) is high after reset. Software can disable
the auto-negotiation function by writing to bit
MR0.12.
The contents of register MR4 are sent to the
78Q2123/78Q2133’s
negotiation via fast link pulse coding.
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register
This function can be disabled through
bit
link
MR16.15
partner
is
Register bits
during
The auto-
©
set,
2006 Teridian Semiconductor Corporation
SQE is
auto-
The
the
REGISTER.BITS
The default values of the auto-negotiation registers
are set as follows:
These default values can be changed by writing
different values to the registers, then restarting auto-
negotiation.
With
78Q2123/78Q2133 will start sending fast link pulses
at power on, loss of link or upon a command to
restart.
10BASE-T idle, 100BASE-TX idle, or fast link pulses
from its link partner. If either idle pattern is detected,
the 78Q2123/78Q2133 configure themselves in half-
duplex mode at the appropriate speed. If it detects
fast link pulses, it decodes and analyzes the link
code transmitted by the link partner. When three
identical link code words are received (ignoring the
acknowledge bit) the link code word is stored in
register MR5. Upon receiving three more identical
link code words, with the acknowledge bit set, the
78Q2123/78Q2133 configure themselves to the
highest priority technology common to the two link
partners.
descending order:
Once auto-negotiation is complete, register bits
MR18.11:10 will reflect the actual speed and duplex
that was chosen.
If auto-negotiation fails to establish a link for any
reason, register bit MR18.12 will reflect this and auto
negotiation will restart from the beginning. Writing a
‘1’ to bit MR0.9 (RANEG) will also cause auto-
negotiation to restart.
4.8/1.14
4.7/1.13
4.6/1.12
4.5/1.11
0.13
0.12
0.8
100BASE-TX, Full Duplex
100BASE-TX, Half Duplex
10BASE-T, Full Duplex
10BASE-T, Half Duplex
At the same time, it will look for either
auto-negotiation
78Q2123/78Q2133 MicroPHY™
The
10/100BASE-TX Transceiver
100 BASE-TX
Speed Select
100BASE-TX
FUNCTION
Full Duplex
10 BASE-T
Full Duplex
10 BASE-T
AN Enable
technology
Duplex
priorities
DEFAULT VALUE
enabled,
1 (100 BASE TX)
1 (full duplex)
1 (enabled)
1
1
1
1
are,
Rev 1.1
the
in