ETC 84C300A

Full Duplex
84C300A
84C300A 4-Port
Fast
Ethernet Controller
HURRICANE
4-Port
TM
Fast Ethernet Controller
98078
Features
Note: Check for latest Data Sheet revision
before starting any designs.
■ Low Power CMOS Technology
SEEQ Data Sheets are now on the Web, at
www.lsilogic.com.
■ 4-Port Ethernet Controller Optimized for
Switching Hub, Multiport Bridge/Router,
Server Applications
This document is an LSI Logic document. Any
reference to SEEQ Technology should be
considered LSI Logic.
■ Supports 100Base-T4, 100 Base-TX, 100Base-FX
& 10Base-T Transceivers
■ Meets ANSI/IEEE 802.3 and ISO 8802-3 Standards
for Thicknet (10Base-5), Thin Net (10Base-2)
and Twisted Pair (10Base-T)
- Receive CRC Mode
- Disable Self-Receive on Transmits Mode
- Disable Further Transmissions when Both
Transmit Status Registers are Full
- Disable Loading the Transmit Status for
Successfully Transmitted Packets
- Disable the Receive Interrupts Independent
of the Receive Command Register Setting
■ Standard 10MBit/sec Serial Mode or
Programmable MII Ethernet Interface for 10/100
MBit/sec Applications
■ Preamble Generation and Removal
■ Automatic 32-Bit FCS (CRC) Generation and
Checking
■ Collision Handling, Transmission Deferral and
Retransmission with Automatic Jam and
Backoff Functions
■ Six Counters per Port for Network
Management Statistics
Receive:
- 16 Bit CRC Errors
- 16 Bit Runt Frames
- 8 Bit Oversize Frames
- 16 Bit Alignment Errors
Transmit:
- 16 Bit Transmit Collisions
- 16 Bit Total Collisions
■ Transmit Status on a Per Packet Basis Reports the
Following
- Occurrence of a Transmit FIFO Underflow
- Transmit Collision Occurrence
- 16 Collision Occurrence
- Carrier Sense Error During Transmission
- 10/100 Mbit/sec Transmit Clock Detect
- Late Collision Occurrence
- Transmission Successful
- Transmission Deferred
■ Full Duplex Operation
- Provides 20/200 Mbps Bandwidth for
Switched Networks
- Supports AutoDUPLEX Mode for Automatic
Full Duplex Operation
■ Single 5 V± 5% Power Supply
■ Loopback Capability for Diagnostics
■ The Following Additional Features can be
Programmed for the 84C300A
- 64 bit Multicast Filter
- Reports Status of “SQE” During Transmits
- Transmit No CRC Mode
- Transmit No Preamble Mode
- Transmit Packet Autopadding Mode
■ High Bandwidth Bus Interface
- 32 Bits x 33 MHz
- Selectable Big/Little Endianess
■ Independent 128 Byte Transmit/Receive
FIFOs/Port
- Programmable Threshold Flags
■ 208 Pin PQFP package
Hurricane is a trademark of SEEQ Technology Inc.
4-1
1
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
Table of Contents
1.0 Pin Description
3.6.6
3.6.7
3.6.8
3.6.9
Receive Status Register
Configuration Registers
FIFO Threshold Register
Defer Register Calculations for
the 84C300A
3.6.10 Transmit Control/Product I.D. Register
3.6.11 Full Duplex Status Register
2.0 Introduction
3.0 Functional Description
3.1 Frame Format
3.2 Packet Transmission per Port
3.2.1 Controlling Transmit Packet
Encapsulation
3.2.2 Transmission Initiation/Deferral
3.2.3 Collision on Transmit
3.2.4 Transmit Termination Conditions
3.2.5 Conditions That Will Cause a Port’s
TXRET Pin to go HIGH
3.2.6 Detecting and Clearing a
Transmit Retry Condition
3.7 Counters
3.7.1 Accessing the Counters
3.7.2 Counter Value after Read Operation
Completion
3.7.3 Counter Behavior Upon Reading
Maximum Count
3.7.4 Counter Interrupt Condition
4.0 DC Characteristics
3.3. Packet Reception Per Port
3.3.1 Preamble Processing
3.3.2 Address Matching
3.3.3 Terminating Reception
3.3.4 Using the RXABORT Pins to Terminate
Reception of a Packet
3.3.5 Receive Discard Conditions
5.0 Command/Status Interface Timing
5.01 Command/Status Interface Read Timing
5.02 Command/Status Interface Write Timing
6.0 Transmit Interface Timing
6.01 Ethernet Transmit Interface Timing
6.02 Ethernet Receive Interface Timing
3.4 System Interface
3.5 FIFO Interface
3.5.1 Little Endian and Big Endian Format
3.5.2 Transmit FIFO Interface
3.5.3 Receive FIFO Interface
3.5.4 Special Conditions on
RXRD_TXWR Clock Input
7.0 Transmit Data Interface Write Timing
7.01 Transmit Data Interface Write Timing 1
7.02 Transmit Data Interface Write Timing 2
8.0 Receive Data Interface Read Timing
3.6 Register Interface
3.6.1 Internal Port Register Addressing
Table
3.6.2 Station Address Register
3.6.3 Transmit Command Register
3.6.4 Transmit Status Register
3.6.5 Receive Command Register
8.01 Receive Data Interface Read Timing 1
8.02 Receive Data Interface Read Timing 2
9.0 Transmit Data Interface Timing on
Exception Conditions
10.0 Receive Data Interface Timing on
Exception Conditions
Illustrations
11.0 Reset Timing
Figure 1. Functional Block Diagram of the 84C300A
Figure 2. 84C300A Pin Configuration
Figure 3. Typical Application Example
2
4-2
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
1.0 Pin Description
Pin
Pin Name
I/O
Description
Chip Registers’ Interface
22
ENREGIO
I
Enable Register I/O Operations
This active low input enables the chip for register operations. This input must be
low before any port’s registers can be written or read.
4
W R
I
Write Strobe
For a selected port within the chip, this input acts as a write strobe for one of the port’s
registers. The port is selected through the REGPS[1:0] inputs and the register is
addressed through the A[3:0] address inputs. The data being written appears on the
CDST[7:0] data lines and must be set up relative to the rising edge of the write strobe.
This input is active low.
5
RD
I
Read Strobe
For a selected port within the chip, this input acts as a read strobe for one of the port’s
registers. The port is selected through the REGPS[1:0] inputs and the register is
addressed through the A[3:0] address inputs. When the read strobe is active low,
the output drivers for CDST[7:0] data bus are enabled. Valid register data appears
on the data bus a specified time before the rising edge of the read strobe.
REGPS[1:0]
I
Register Port Select Inputs
These inputs are used to select which port’s registers are read or written by asserting
the RD or WR read or write strobe inputs. Binary values of 00 through 11 select
channels 1 through 4 respectively with REGPS1 being the MSB of the binary value.
21, 20
REGPS1 REGPS0
0
0
1
1
153,
6, 7, 8
A[3:0]
9-12
15-18
47, 61,
68, 77
49
0
1
0
1
Port 1
Port 2
Port 3
Port 4
I
Register Select Address
These inputs are the address lines used to select which register within a port is being
read or written. A3 (153) has an internal pull down.
CDST[7:0]
I/O
Register Data
These bidirectional lines carry register data to or from the internal registers of each
port in the chip. These lines are nominally high impedance until their output drivers
are enabled by the RD and ENREGIO input pins being driven low.
INT_[1:4]
O
Interrupts
These outputs are driven by a variety of Transmit and Receive interrupt conditions
of a particular port. If remains HIGH until the corresponding port’s Status Register
containing the reason for the interrupt is read.
RESET
I
Hardware Reset
This input is an active low asynchronous chip reset. After reset, all registers except
the Hash and Station Address registers are reset to zero, all FIFOs are cleared, all
counters are reset to zero.
4-3
3
MD400152/E
Selected
Port
84C300A 4-Port
Fast Ethernet Controller
Pin Description (cont.)
Pin
Pin Name
I/O
Description
Receive and Transmit FIFO Interface
31
RXINTEN
I
Receive Interface Enable
This is an active low input that acts as a chip enable to enable the receiver interface.
Driving this pin active enables the output drivers for the RXDC[1:4] and RXRDY[1:4],
pins. Also, this pin must be driven active before receive FIFO reads can be
performed.
32
TXINTEN
I
Transmit Interface Enable
This is an active low input that acts as a chip enable to enable the transmitter
interface. Driving this pin active enables the output drivers for the TXRET[1:4],
TXRDY[1:4] pins. Also, this pin must be driven active before transmit FIFO writes
can be and performed.
36
RXRDEN
I
Receive Read Enable
This is an active low input that, when driven active with the RXINTEN pin, enables
read operations from one of the four receive FIFOs within the chip.
37
TXWREN
I
Transmit Write Enable
This is an active low input that, when driven active with the TXINTEN pin, enables
write operations to one of the four transmit FIFOs within the chip.
35
RXRD_TXWR
I
Receive Read Transmit Write Clock
This clock input is also the chip’s read/write strobe to the chip’s eight
receive/transmit FIFOs. With the TXINTEN and TXWREN inputs active low,
this input becomes the write strobe for writing transmit data to one of the chip’s
transmit FIFOs. Similarly, with the RXINTEN and RXRDEN inputs active low, this
input becomes the read strobe for reading receive data from one of the chip’s receive
FIFOs. This input must be connected to a continuous clock whose maximum
frequency can be 33 MHz.
30, 29
RXTXPS[1:0]
I
Port Select
These inputs are used to select and identify which port will be accessed for the
following operations.
1. Receive FIFO Reads
2. Transmit FIFO Writes
3. Clearing a TXRET Condition
4. Clearing a RXDC Condition
5. Aborting a Receive Packet
RXTXPS[1:0]
23, 24
25, 26
RXTXBE[3:0]
I
RXTXPS1
RXTXPS0
Selected
Port
0
0
1
1
0
1
0
1
Port 1
Port 2
Port 3
Port 4
Receive Transmit Byte Enable
These are active low inputs that determine which bytes of the double
word for a receive FIFO read are driven with valid data or which bytes of a double
word being written to a transmit FIFO contain valid data.
4
4-4
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
Pin Description (cont.)
Pin
Pin Name
I/O
44, 57
64, 73
TXRDY_ [1:4]
O
Transmit Ready
These are active high three state outputs. When enabled, these outputs function as
a flag that indicates whether the associated port’s transmit FIFO has enough space
available to meet the threshold value programmed in the FIFO threshold register.
When enabled, a high value on any of these outputs indicates that the associated
port’s transmit FIFO has greater than or equal to the threshold number of double word
spaces available in the FIFO and a low value indicates it does not. The tristate drivers
for all these outputs are enabled by a low value on the TXINTEN input pin.
42, 56
63, 72
RXRDY_ [1:4]
O
Receive Ready
These are active high three state outputs. When enabled, these outputs function as
a flag that indicates whether the associated port’s receive FIFO has enough data
available to meet the threshold value programmed in the FIFO threshold register.
When enabled, a high value on any of these outputs indicates that the associated
port’s receive FIFO has greater than or equal to the threshold number of double
words available in the FIFO or has a completed receive packet in the FIFO as
indicated by the packets status double word being in the FIFO. The tristate drivers
for all these outputs are enabled by a low value on the RXINTEN input pin.
39
SPDTAVL
O
Space Data Available
This is an active high output that can be used for validating reads from the receive
FIFO during a read operation and preventing over writes to the transmit FIFO during
a write operation. For further details, please refer to the Transmit Data Write Timing
and the Receive Data Read Timing diagrams.
40
RXTXEOF
I/O
Receive Transmit End of Frame
This is a bidirectional pin that is used to signal the last double word of a transmit or
receive packet. During receive FIFO reads this pin is enabled as an output and when
detected high indicates that the last double word of a receive packet has been read
from the receive FIFO. During transmit FIFO writes this pin is an input and when
asserted high during a write it indicates that this is the final double word of a transmit
packet. In the transmit FIFO write case the value of this signal is stored as the 33rd
bit in the FIFO. In the receive FIFO read case the value of this signal is read out as
the 33rd bit of the receive FIFO.
41
TXNOCRC
I
Transmit No CRC
This active high input is used to control appending of a CRC to a transmit packet.
A transmit packet can be made to exclude appending a CRC value if this input is held
high any time during a packet write to the transmit FIFO. Transmission of all packets
without CRC can be done by setting bit #4 of configuration register #1. It should be
noted that TXNOCRC pin can be used to control CRC encapsulation only on a per
packet basis.
I/O
Receive/Transmit Data
This is the bidirectional data bus for reads from the receive FIFO or writes to the
transmit FIFO of the chip. Bus direction is controlled via RXINTEN and RXDEN for
reads; TXINTEN and TXWREN are used for writes. Data is clocked with the
RXRD_TXWR strobe input.
80-84
86-89
91-94
96-101
107-112
115-121
R
X
T
X
D
A
T
A
[
3
1
:
0
]
Description
4-5
5
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
Pin Description (cont.)
Pin
Pin Name
I/O
Description
Transmit and Receive Exception Indicators
48, 62
71, 79
TXRET_ [1:4]
O
Transmit Retry
These are active high tristate outputs. All four of these output pins are driven by
tristate drivers enabled by an active low being driven onto the TXINTEN input pin.
Once enabled, a high value on any of these inputs indicates that the associated port
could not complete transmission of a packet due to one of the following conditions
and that a retransmission of the packet is requested:
1. A late collision occurred during transmission.
2. Carrier sense never went high or dropped out
during transmission.
3. During a transmission attempt a transmit FIFO underflow error occurred.
4. 16 attempts to transmit the packet all resulting in transmit collisions.
Internally, the TXRET signal will remain high until it is cleared by the CLRTXERR pin,
(See the text on clearing error conditions). As long as the internal TXRET signal for
a port remains high, that port’s transmit FIFO will remain cleared and no new
transmissions can occur.
45, 58
65, 74
RXDC_ [1:4]
O
Receive Discard
These are active high tristate outputs. All four of these outputs pins are driven
by tristate drivers enabled by a low value being driven onto the RXINTEN input pin.
Once enabled, a high value on any of these inputs indicates that the associated port
discarded reception of a packet due to one of the possible receive discard conditions.
Internally, a port’s RXDC signal will remain high until it is cleared by the CLRRXERR
pin, (See the text on "Receive Discard Conditions"). As long as the internal RXDC
signal for a port remains high, that port’s receive FIFO will remain cleared and no new
packets will be received.
Special Purpose Pins
38
CLRTXERR
I
Clear Transmit Error
This active high input is used to clear transmit retry flags within the chip. See the
"Receive Discard Conditions" section for how this input is used.
50
CLRRXERR
I
Clear Receive Error
This active high input is used to clear Receive Discard flags within the chip. See the
"Receive Discard Conditions" section for how this input is used.
RXABORT_[1:4]
I
Receive Abort
These inputs, when pulse high concedes the corresponding port to abort
reception of a frame.
FDUPLX_[1:4]
I
Full Duplex Mode
These active low inputs are used to set the corresponding port into Full Duplex mode.
In this mode, the corresponding transmitter will not defer to an active carrier
sense signal.
ONETRYMODE
I
This input when tied high will cause any of the 84C300A ports to drive it’s corresponding TXRET to a HIGH state for a particular port if during transmission it encounters
a collision contention. The controller will not automatically attempt to retransmit a
packet/frame when this input pin is high. Transmit FIFO is flushed of data and the
new packet/frame needs to be reloaded to the FIFO for transmission.
ONETRYMODE has an internal pull-down.
46, 59
67, 75
1
1
2
7
,2
5
1
1
2
4
,2
3
152
6
4-6
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
Pin Description (cont.)
Pin
Pin Name
I/O
Description
Media Independent Interface
138
TXC_1
I
Transmit Clock Port 1
This is the transmit clock input for port #1. In standard 10 Mbit/sec Serial Mode, this
is a 10 Mhz, 50% duty cycle transmit clock used to synchronize the transmit data from
port #1 to the encoder. In this mode, transmit data appears serially on the TXD0_1
output and all transitions of transmit data and the TXEN_1 output occur from the
falling edge of the clock. In MII mode, this is a 2.5/25 Mhz, 50% duty cycle clock, and
the transmit data appears on the TXD0_1 through TXD3_1 outputs. In this mode
transitions of transmit data and the TXEN_1 output occur from the rising edge of the
clock.
161
TXC_2
I
Transmit Clock Port 2
This is the transmit clock input for port #2. In standard 10 Mbit/sec Serial Mode, this
is a 10 Mhz, 50% duty cycle transmit clock used to synchronize the transmit data from
port #2 to the encoder. In this mode, transmit data appears serially on the TXD0_2
output and all transitions of transmit data and the TXEN_2 output occur from the
falling edge of the clock. In MII mode, this is a 2.5/25 Mhz, 50% duty cycle clock, and
the transmit data appears on the TXD0_2 through TXD3_2 outputs. In this mode
transitions of transmit data and the TXEN_2 output occur from the rising edge of the
clock.
177
TXC_3
I
Transmit Clock Port 3
This is the transmit clock input for port #3. In standard 10 Mbit/sec Serial Mode, this
is a 10 Mhz, 50% duty cycle transmit clock used to synchronize the transmit data from
port #3 to the encoder. In this mode, transmit data appears serially on the TXD0_3
output and all transitions of transmit data and the TXEN_3 output occur from the
falling edge of the clock. In MII mode, this is a 2.5/25 Mhz, 50% duty cycle clock, and
the transmit data appears on the TXD0_3 through TXD3_3 outputs. In this mode
transitions of transmit data and the TXEN_3 output occur from the rising edge of the
clock.
TXC_4
I
Transmit Clock Port 4
This is the transmit clock input for port #4. In standard 10 Mbit/sec Serial Mode, this
is a 10 Mhz, 50% duty cycle transmit clock used to synchronize the transmit data from
port #1 to the encoder. In this mode, transmit data appears serially on the TXD0_4
output and all transitions of transmit data and the TXEN_4 output occur from the
falling edge of the clock. In MII mode, this is a 2.5/25 Mhz, 50% duty cycle clock, and
the transmit data appears on the TXD0_4 through TXD3_4 outputs. In this mode
transitions of transmit data and the TXEN_4 output occur from the rising edge of the
clock.
139-142
TXD[3:0]_1
O
Transmit Data Port 1
In standard 10 Mbit/sec Serial Mode, TXD0_1 is the serial transmit data output from
port #1 to the encoder. In MII mode, these outputs drive a nibble of transmit data
every leading edge of the TXC_1 clock from port #1 to the encoder.
162, 163
164, 166
TXD[3:0] _2
O
Transmit Data Port 2
In standard 10 Mbit/sec Serial Mode, TXD0_2 is the serial transmit data output from
port #2 to the encoder. In MII mode, these outputs drive a nibble of transmit data
every leading edge of the TXC_2 clock from port #2 to the encoder.
180, 181
182, 185
TXD[3:0] _3
O
Transmit Data Port 3
In standard 10 Mbit/sec Serial Mode, TXD0_3 is the serial transmit data output from
port #3 to the encoder. In MII mode, these outputs drive a nibble of transmit data
every leading edge of the TXC_3 clock from port #3 to the encoder.
197
4-7
7
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
Pin Description (cont.)
Pin
Pin Name
I/O
TXD[3:0] _4
O
Transmit Data Port 4
In standard 10 Mbit/sec Serial Mode, TXD0_4 is the serial transmit data output from
port #4 to the encoder. In MII mode, these outputs drive a nibble of transmit data
every leading edge of the TXC_4 clock from port #4 to the encoder.
143
TXEN_1
O
Transmit Enable Port 1
This output from port #1 is used to activate the encoder. In standard 10 Mbit/sec
Serial Mode, it becomes active when the first bit of the Preamble is transmitted and
inactive when the last bit of the frame is transmitted. In MII mode, this output
becomes active when the first nibble of the Preamble is transmitted and inactive
when the last nibble of the frame is transmitted. This output is active high.
167
TXEN_2
O
Transmit Enable Port 2
This output from port #2 is used to activate the encoder. In standard 10 Mbit/sec
Serial Mode, it becomes active when the first bit of the Preamble is transmitted and
inactive when the last bit of the frame is transmitted. In MII mode, this output
becomes active when the first nibble of the Preamble is transmitted and inactive
when the last nibble of the frame is transmitted. This output is active high.
186
TXEN_3
O
Transmit Enable Port 3
This output from port #3 is used to activate the encoder. In standard 10 Mbit/sec
Serial Mode, it becomes active when the first bit of the Preamble is transmitted and
inactive when the last bit of the frame is transmitted. In MII mode, this output
becomes active when the first nibble of the Preamble is transmitted and inactive
when the last nibble of the frame is transmitted. This output is active high.
203
TXEN_4
O
Transmit Enable Port 4
This output from port #4 is used to activate the encoder. In standard 10 Mbit/sec
Serial Mode, it becomes active when the first bit of the Preamble is transmitted and
inactive when the last bit of the frame is transmitted. In MII mode, this output becomes
active when the first nibble of the Preamble is transmitted and inactive when the last
nibble of the frame is transmitted. This output is active high.
128
RXC_1
I
Receive Clock Port 1
In standard 10Mbit/sec Serial Mode, this input is a 10Mhz, 50% duty cycle nominal
receive clock which is used to synchronize incoming data from the decoder to port
#1. In 10Mbit/sec Serial Mode CSN and RXD0_1 are assumed to transition from the
leading edge of this clock. In MII mode this clock is a 2.5/25 Mhz, 50% duty cycle
receive clock that synchronizes incoming nibble wide data from the decoder to port
#1. In MII mode data and the RXDV signal are assumed to transition from the falling
edge of the clock.
146
RXC_2
I
Receive Clock Port 2
In standard 10Mbit/sec Serial Mode, this input is a 10Mhz, 50% duty cycle nominal
receive clock which is used to synchronize incoming data from the decoder to port
#2. In 10Mbit/sec Serial Mode CSN and RXD0_2 are assumed to transition from the
leading edge of this clock. In MII mode this clock is a 2.5/25 Mhz, 50% duty cycle
receive clock that synchronizes incoming nibble wide data from the decoder to port
#2. In MII mode data and the RXDV signal are assumed to transition from the falling
edge of the clock.
198, 199
201, 202
Description
8
4-8
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
Pin Description (cont.)
Pin
Pin Name
169
RXC_3
I/O
I
Receive Clock Port 3
In standard 10Mbit/sec Serial Mode, this input is a 10Mhz, 50% duty cycle nominal
receive clock which is used to synchronize incoming data from the decoder to port
#3. In 10Mbit/sec Serial Mode CSN and RXD0_3 are assumed to transition from the
leading edge of this clock. In MII mode this clock is a 2.5/25 Mhz, 50% duty cycle
receive clock that synchronizes incoming nibble wide data from the decoder to port
#3. In MII mode data and the RXDV signal are assumed to transition from the falling
edge of the clock.
Description
188
RXC_4
I
Receive Clock Port 4
In standard 10Mbit/sec Serial Mode, this input is a 10Mhz, 50% duty cycle nominal
receive clock which is used to synchronize incoming data from the decoder to port
#4. In 10Mbit/sec Serial Mode CSN and RXD0_4 are assumed to transition from the
leading edge of this clock. In MII mode this clock is a 2.5/25 Mhz, 50% duty cycle
receive clock that synchronizes incoming nibble wide data from the decoder to port
#4. In MII mode data and the RXDV signal are assumed to transition from the falling
edge of the clock.
131, 133
136, 137
RXD[3:0]_1
I
Receive Data Port 1
In standard 10 Mbit/sec Serial Mode, RXD0_1 is the serial input data to port #1 from
the decoder. In MII mode, these inputs are driven with a nibble of receive data every
falling edge of the RXC_1 clock from the encoder to port #1.
149, 150
151, 160
RXD[3:0]_2
I
Receive Data Port 2
In standard 10 Mbit/sec Serial Mode, RXD0_2 is the serial input data to port #2 from
the decoder. In MII mode, these inputs are driven with a nibble of receive data every
falling edge of the RXC_2 clock from the encoder to port #2.
172-175
RXD[3:0]_3
I
Receive Data Port 3
In standard 10 Mbit/sec Serial Mode, RXD0_3 is the serial input data to port #3 from
the decoder. In MII mode, these inputs are driven with a nibble of receive data every
falling edge of the RXC_3 clock from the encoder to port #3.
192
194-196
RXD[3:0]_4
I
Receive Data Port 4
In standard 10 Mbit/sec Serial Mode, RXD0_4 is the serial input data to port #4 from
the decoder. In MII mode, these inputs are driven with a nibble of receive data every
falling edge of the RXC_4 clock from the encoder to port #4.
130
CSN_1
I
Carrier Sense Port 1
This is port #1's carrier sense input which indicates there is traffic on the transmission
medium connected to port #1. Carrier sense becomes active with the first bit of the
Preamble received, and inactive one bit time after the last bit of the frame is received.
This is an active high input.
129
RX_DV_1
I
Receive Data Valid Port 1
In MII mode this input is receive data valid. Receive data valid becomes active with
the first nibble of synchronized and decoded Preamble or SFD appearing on the
RXD[3:0]_1 lines and goes inactive one clock time after the last nibble of the frame
is received. This is an active high input.
148
CSN_2
I
Carrier Sense Port 2
This is port #2's carrier sense input which indicates there is traffic on the transmission
medium connected to port #2. Carrier sense becomes active with the first bit of the
Preamble received, and inactive one bit time after the last bit of the frame is received.
This is an active high input.
4-9
9
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
Pin Description (cont.)
Pin
Pin Name
I/O
Description
147
RX_DV_2
I
Receive Data Valid Port 2
In MII mode this input is receive data valid. Receive data valid becomes active with
the first nibble of synchronized and decoded Preamble or SFD appearing on the
RXD[3:0]_2 lines and goes inactive one clock time after the last nibble of the frame
is received. This is an active high input.
171
CSN_3
I
Carrier Sense Port 3
This is port #3's carrier sense input which indicates there is traffic on the transmission
medium connected to port #3. Carrier sense becomes active with the first bit of the
Preamble received, and inactive one bit time after the last bit of the frame is received.
This is an active high input.
170
RX_DV_3
I
Receive Data Valid Port 3
In MII mode this input is receive data valid. Receive data valid becomes active with
the first nibble of synchronized and decoded Preamble or SFD appearing on the
RXD[3:0]_3 lines and goes inactive one clock time after the last nibble of the frame
is received. This is an active high input.
191
CSN_4
I
Carrier Sense Port 4
This is port #4's carrier sense input which indicates there is traffic on the transmission
medium connected to port #4. Carrier sense becomes active with the first bit of the
Preamble received, and inactive one bit time after the last bit of the frame is received.
This is an active high input.
190
RX_DV_4
I
Receive Data Valid Port 4
In MII mode this input is receive data valid. Receive data valid becomes active with
the first nibble of synchronized and decoded Preamble or SFD appearing on the
RXD[3:0]_4 lines and goes inactive one clock time after the last nibble of the frame
is received. This is an active high input.
145
COLL_1
I
Collision Port 1
This input indicates that a transmission contention has occurred on the transmission
medium connected to port #1. The collision input is latched internally. Sampled
during transmission, Collision is set by an active high pulse on the COLL input and
automatically reset at the end of transmission of the JAM sequence.
168
COLL_2
I
Collision Port 2
This input indicates that a transmission contention has occurred on the
transmission medium connected to port #2. The collision input is latched
internally. Sampled during transmission, Collision is set by an active
high pulse on the COLL input and automatically reset at the end of
transmission of the JAM sequence.
187
COLL_3
I
Collision Port 3
This input indicates that a transmission contention has occurred on the
transmission medium connected to port #3. The collision input is latched
internally. Sampled during transmission, Collision is set by an active high
pulse on the COLL input and automatically reset at the end of transmission
of the JAM sequence.
10
4-10
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
Pin Description (cont.)
Pin
Pin Name
204
COLL_4
I
Collision Port 4
This input indicates that a transmission contention has occurred on the
transmission medium connected to port #4. The collision input is
latched internally. Sampled during transmission, Collision is set by an
active high pulse on the COLL input and automatically reset at the end
of transmission of the JAM sequence.
205
DAISY_OUT
O
Test Mode
This output is used for parametric test of the I/O’s only. It should not
be externally connected.
2, 14, 28, 33,
52, 53, 70,
78, 102, 104,
114, 126, 132,
135, 154, 157,
158, 178, 183,
189, 193
VDD
—
Power Supply 5V +/– 5%
1, 3, 13
19, 27, 34,
43, 51, 54,
55, 60, 66,
69, 76, 85,
90, 95, 103,
105, 106, 113,
122, 134,
144, 155,
156, 159,
165, 176,
179, 184,
200, 207,
208
GND
—
Ground 0 Volts
NC
—
No Connect
206
I/O
Description
Note: All inputs must never be left floating even if they are not in use. For example the RX_DV pins must be driven either
HIGH or LOW even if the corresponding channel is not in MII mode. Exceptions to this rule are the pins onetrymode (152),
and A3 (153) which have internal pull downs.
4-11
11
MD400152/E
MD400152/E
PARALLEL
/SERIAL
CRC/DATA SELECT
RXNOCRC
CONTROL
REGISTER
FILE
CRC
GENERATOR
MODE 100
INTERRUPT
AND
CONTROL
REGISTER
INTERFACE
& TRI-STATE
LOGIC
M
U
X
M
U
X
TXD0
INTn
CDST [7:0]
WR
RD
REGPS [1:0]
A [3:0]
84C300A 4-Port
Fast Ethernet Controller
12
4-12
#208
TXD3 4
TXD2_4
TXD1_4
TXEN_4
TXD0_4
DAISY_OUT
COLL_4
GND
#200-
-#1
V DD
NC
GND
GND
GND
84C300A 4-Port
Fast Ethernet Controller
GND
WR
A3
RD
A2
A1
A0
CDST7
CDST6
-#10
CDST5
CDST4
GND
V DD
CDST3
CDST2
GND
REGPS0
RXTXBE3
RXTXBE2
84C300A
84C300(20
8 PQFP)
(208
PQFP)
RXTXBE0
GND
VD
TXINTEN
FDUPLX_2
FDUPLX_3
GND
FDUPLX_4
RXRDEN
VD
TXRET_1
GND
Figure 2. 84C300A Pin Configuration
4-13
13
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
2.0 Introduction
3.0 Functional Description
The 84C300A is a 4-Port Ethernet Media Access Controller (MAC) with a rich set of operating modes and features.
It is manufactured as a single-chip VLSI device to simplify
and enhance the development of multi-port Ethernet embedded systems such as bridges, switches, and routers.
On an Ethernet communication network, information is
transmitted and received in packets or frames. An Ethernet frame consists of a preamble, two address fields, a
byte-count field, a data field and a frame check sequence
(FCS). Each field has a specific format which is described
in detail below. An Ethernet frame has a minimum length
of 64 bytes and a maximum length of 1518 bytes exclusive
of the preamble. The Ethernet frame format is shown in the
figure below.
Two input/output paths are provided for interfacing to
physical layer devices. In IEEE-standard MII mode, the
84C300A provides an industry standard interface supporting both 10Mbit/sec and 100Mbit/sec data rates. This
interface will directly connect with physical layer devices
such as SEEQ’s 80C240 100Base-T4 PHY without additional glue logic. In Serial mode, the chip supports the
standard Ethernet CSMA/CD protocol via a serial interface
for transmit and receive data. All ports, in all interface
modes, support both Half and Full Duplex operation.
3.1 FRAME FORMAT
ETHERNET FRAME
PREAMBLE
(8)
Each port of the 84C300A is feature compatible with
SEEQ’s 80C300 Ethernet Media Access Controller.
These features include: 64 bit Multicast filter, Transmit no
CRC, Transmit no Preamble, Transmit Packet
Autopadding, Receive CRC, Receive Own Transmit Disable, Receive Group Address Mode, Fast Receive Discard Mode, and Full Duplex Mode. Additionally, each port
supports: programmable defer time between transmit
packets, appending value of FCS on a packet-by-packet
basis, and pin-controllable per-port receive packet abort.
DESTINATION
ADDRESS
(6)
SOURCE
ADDRESS
BYTE
(6)
COUNT
(2)
DATA
(46-1500)
NOTE:
Field length bytes, in parentheses.
FIRST BYTE
......
A0
A15 . . . . . .
A8
A7
A23 . . . . . . A16
A high-bandwidth universal system interface is provided
which is compatible with many microprocessor or system
busses, easing the integration of the 84C300A into many
system architectures. Its 32-bit data path width is provided
to provide the bandwidth necessary to maintain full duplex
wire speed communications simultaneously through all
four ports. Each port is provided with dual 128 byte FIFOs
to ease bus multiplexing and interfacing to different clock
domains.
A31 . . . . . . A24
DESTINATION
ADDRESS
(6 BYTES)
A39 . . . . . . A32
A47 . . . . . . A40
......
B0
B15 . . . . . .
B8
B7
B23 . . . . . . B16
B31 . . . . . . B24
SOURCE
ADDRESS
(6 BYTES)
B39 . . . . . . B32
B47 . . . . . . B40
......
T0
T15 . . . . . .
T8
......
D0
T7
D7
BYTE COUNT
(2 BYTES)
DATA
(46 – 1500
BYTES)
LAST BYTE
Typical Frame Buffer Format for
Byte-Organized Memory
14
4-14
MD400152/E
FCS
(4)
84C300A 4-Port
Fast Ethernet Controller
Preamble: The preamble is a 64-bit field consisting
of 62 alternating “1”s and “0”s followed by a “11” Endof-Preamble indicator.
written to the port’s transmit FIFO by the system. Similarly,
a port can be prevented from appending an FCS value to
a packet by setting bit #4 HIGH in the Configuration
Register #1. As long as this bit is high, any packet
transmitted by the port will not include an FCS value unless
it is written as part of the transmit data written to the port's
transmit FIFO. Appending of a FCS value can be controlled on a packet per packet basis by using the
TXNOCRC pin as long as the TXNOCRC Tx-Rx Configuration register bit has not been set high. If the TXNOCRC
pin is held high (or) if the TXNOCRC bit is set anytime
during the duration of a packet write to the transmit FIFO,
that particular packet will not be appended with a CRC
value.
Destination Address: The Destination Address is a
6-byte field containing either a specific Station
Address, a Broadcast Address, or a Multicast
Address to which this frame is directed.
Source Address: The Source Address is a 6-byte
field containing the specific Station Address from
which this frame originated.
Byte-Count Field: The Byte-Count Field consists of
two bytes providing the number of valid data bytes in
the Data Field, 46 to 1500. This field is uninterpreted
at the Data Link Layer, and is passed through the
EDLC chip to be handled at the Client Layer.
Transmit No CRC
CRC Appendage
H/W Pin 41
S/W Bit 4
of Config 1
To the Packet
Data Field: The Data Field consists of 46 to 1500
bytes of information which are fully transparent in the
sense that any arbitrary sequence of bytes may occur.
0
0
Yes
0
1
No
1
0
No
Frame Check Sequence: The Frame Check
Sequence (FCS) field is a 32-bit cyclic redundancy
check (CRC) value computed as a function of the
Destination Address Field, Source Address Field,
Type Field and Data Field. The FCS is appended to
each transmitted frame, and used at reception to
determine if the received frame is valid.
1
1
No
Please note that both the H/W pin and the software bit
should be kept deasserted during the entire duration of the
packet write to the transmit FIFO in order to transmit a
packet with CRC.
3.2.2 Transmission Initiation in Full Duplex and
CSMA/CD Networks
3.2 PACKET TRANSMISSION PER PORT
The transmit data stream consists of the Preamble, four
information fields, and the FCS which is computed in real
time by the port and automatically appended to the frame
at the end of the data. The Preamble is also generated by
the port and transmitted immediately prior to the Destination Address. Destination Address, Source Address, Type
Field and Data Field are prepared in the buffer memory
prior to initiating transmission. The port encapsulates
these fields into an Ethernet frame by inserting a preamble
prior to these information fields and appending a CRC after
the information fields. A port can be programmed to
exclude inclusion of the preamble and/or the FCS from the
transmit data stream. In this case, it is assumed that the
preamble and FCS are provided as part of the data written
to the port.
Packet transmission begins with one of the following
conditions:
1. Data in the transmit FIFO meets or exceed a userdefined threshold value or,
2. An EOF is asserted with the last data word written
into the transmit FIFO.
The transmit threshold value is controlled by programming
bits 7 through 4 of the Transmit Control/Product ID register. The default value is 0 (zero), which enables the MAC
to begin packet transmission with as little as one double
word in the FIFO. The threshold, measured in double
words, is equal to the number programmed into Transmit
Control Register times 2. Thus, if the register contains the
value 3H, transmission is deferred until there are at least
6 double words of data in the FIFO.
3.2.1 Controlling Transmit Packet Encapsulation
As was mentioned in the previous paragraph, a port can be
programmed for exclusion of the FCS and/or the preamble
when transmitting a packet. To program a port for transmitting a packet without creating a preamble, bit #2 of the
port’s Configuration Register #1 can be written high. Once
this bit is set, all packets transmitted by the port will not
include a preamble pattern unless it is part of the data
Packet transmission initiation is also dependent upon
whether the 84C300A is in Full Duplex or CSMA/CD mode.
If the Chip is in CSMA/CD mode, transmission may also be
prevented or delayed due to activity on the shared network
4-15
15
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
retransmit the packet. If a packet reaches 16 retransmission attempts without success due to collisions, or if a
collision occurs later than 64 Byte times after the beginning
of a transmission, this is considered to represent a serious
network error. Upon any one of these two error conditions
occurring, the selected port’s Transmit FIFO will be
cleared and the corresponding TXRET output will be
driven HIGH. If the TXRET signal was driven HIGH due to
16 transmission attempts, Bit ‘2’ of the transmit status
register gets set indicating the occurrence of 16 collisions.
When either of the two above error conditions occurs,
retransmission of any packets that were in the transmit
FIFO requires first clearing the TXRET error condition and
then reloading the packet or packets in the Transmit FIFO.
medium. If the network is not busy due to other data traffic,
transmission will begin after the appropriate defer time
(from end of previous traffic) has expired. Otherwise,
transmission is delayed until after current data transfers
are complete, and the defer time requirements have been
satisfied. Following the IEEE 802.3 specifications, the
minimum defer time is split into two periods. The beginning
of the defer time occurs upon the transmitter sensing
carrier sense going LOW. Once this case occurs then if
carrier sense is reasserted during the 1st period of the
defer time, the transmitter will reset its defer time counter
and restart the total defer timeout period from 0. If carrier
sense is reasserted during the 2nd period of the total defer
time interval, the transmitter will ignore carrier sense and
start transmission as soon as the defer time is met. The 1st
period of the total defer time is programmable through use
of the transmit defer register. The second period of the
defer time interval is either 3.2 µs or 0.32 µs depending on
whether the chip is in 10Mbit/sec or 100Mbit/sec mode.
The total default defer time for 10Mbit/sec serial mode is
9.6 µs as measured from TXEN going LOW to TXEN going
High assuming the transmit defer register is at 00 hex and
assuming that the TXEN going LOW to CSN going LOW
delay of the physical device is less than 5 TXC clock
periods. When the chip is in Full Duplex mode, transmission of data onto the network occurs independent of
whether carrier sense indicates a busy network condition
or not.
Scheduling of retransmission is determined by a controlled randomization process called Truncated Binary
Exponential Backoff. The chip waits a random interval
between 0 and 2 K slot times (51.2 µs per slot time for 10
Mbit Ethernet or 5.12 µs per slot time for 100 Mbit Ethernet)
before attempting retransmission, where “K” is the current
transmission attempt number (not to exceed 10).
3.2.4 Transmit Termination Conditions
A port will terminate transmission under the following
conditions.
Normal: The frame has been transmitted success
fully without contention. Loading of the last data byte
into a port’s Transmit FIFO is signaled to the port by
activation of its RxTxEOF signal concurrently with the
last double word of data loaded into the Transmit
FIFO. This line acts as a thirty-third bit in the Transmit
FIFO. When the last valid byte of the last double word
has been transmitted, if the port is not in Transmit No
CRC mode, then the CRC is appended and transmitted concluding frame transmission. The Transmission Successful bit of the Transmit Status Register will
be set by a normal termination.
Because of the variability in delays given for TXEN going
LOW to CSN going LOW for different 100Mbit/sec physical
devices, the default defer time in 100 Mbit/sec MII mode
has been set assuming full duplex conditions where carrier
sense is not monitored by the transmitter. In this case the
default is 0.96 µs from TXEN going LOW to TXEN going
HIGH. To adjust the defer time to some other value, the
programmable defer register can be set using the formulas
given in the section describing the defer register. When
transmission begins, the chip activates the transmit enable (TXEN) line concurrently with the transmission of the
first bit, or first nibble in the MII case, of the Preamble and
keeps it active for the duration of the transmission.
Collision: Transmission attempted by two or more
Ethernet nodes. The Jam sequence is transmitted,
the Collision status bit is set, transmit Collision
Counter is updated, the Backoff interval begun, and
the Transmit FIFO address is set to point to the
beginning of the packet for retransmission.
3.2.3 Collision on Transmit
On the occurrence of a transmit collision condition that
does not represent the 16th transmission attempt for the
packet or does not occur after 64 byte times into the
transmission, the controller will automatically attempt to
retransmit the packet. First, the controller will halt the
transmission of data from the FIFO and begin transmitting
a Jam pattern consisting of 55555555 hex. The controller
will also reset the Transmit FIFO read address pointer
back to the beginning of the transmit packet within the
FIFO. At the end of transmitting the Jam pattern the
controller will then begin the Backoff wait period. Once the
backoff period is finished the controller will automatically
Underflow: Transmit data is not ready when needed
for transmission. Once transmission has begun, a
port on average requires one transmit double word
every 3200 ns for 10 Mbit Ethernet or 320 ns for 100
Mbit Ethernet in order to avoid Transmit FIFO under
flow (starvation). If this condition occurs, the port terminates the transmission, issues a TXRET signal,
and sets the Transmit-Underflow status bit.
16
4-16
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
TRANSMIT
RECEIVE
DATA
BUFFER
DMA/
BUFFER
CONTROL
80C240 10/100Base-T4
or 80220/21 10/100Base-TX
MEDIA INTERFACE
ADAPTER WITH ONCHIP
FILTERS
BUS
TRANSCEIVER
84C300A
4 CHANNEL
QUAD
CPU
80C240 10/100Base-T4
or 80220/21 10/100Base-TX
MEDIA INTERFACE
ADAPTER WITH ONCHIP
FILTERS
SYSTEM
MEMORY
80C240 10/100Base-T4
or 80220/21 10/100Base-TX
MEDIA INTERFACE
ADAPTER WITH ONCHIP
FILTERS
80C240 10/100Base-T4
or 80220/21 10/100Base-TX
MEDIA INTERFACE
ADAPTER WITH ONCHIP
FILTERS
Figure 3. Typical Application Example
16 Transmission Attempts: If a Collision occurs for
the sixteenth consecutive time, the 16-TransmissionAttempts status bit is set, the Collision status bit is set,
the TXRET signal is generated, and the Backoff
interval begun. The counter that keeps track of the
number of collisions is modulo 16 and therefore rolls
over on the 17th collision. Bits 15 to 11 of a port’s
transmit collision counter allow a user to determine
how many transmission attempts were necessary to
successfully transmit the packet.
3.2.5 Conditions That Will Cause a Port’s TXRET Pin
to go High
Detection of a HIGH value on one of the chips 4 TXRET
pins indicates that the associated port could not complete
transmission of a packet due to one or more of the
following conditions:
1. A transmit FIFO underflow occurred while
transmitting the packet.
2. A late collision occurred while transmitting
the packet.
Late Collision: If a Collision occurs greater than 64
byte times after the transmission begins this is considered a late collision error. Upon this condition the
transmission is terminated, the TXRET output is
driven HIGH, and the late collision status bit is set.
3. Carrier sense never went active during
transmission or went from an active to inactive
state during transmission.
4. 16 attempts to transmit the packet all resulted in
transmit collisions.
At the completion of every transmission or retransmission,
new status information is loaded into the Transmit Status
Register. Dependent upon the bits enabled in the Transmit Command Register, an interrupt will be generated for
the just completed transmission.
5. The ONETRYMODE pin is HIGH and a
collision occurs.
Any of the above conditions will cause the port to flush the
transmit FIFO and initiate a transmit retry request. With
initiation of a transmit Retry Request the port’s TXRDY
4-17
17
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
output will go low and stay low until the TXRET flag is
cleared. Similar to a port's receive discard signal, a
transmit retry signal going to the external TXRET pin is
latched upon a transmit retry condition and held high until
cleared. Until a port's transmit retry signal is cleared, no
new transmit packets can be written to the transmit FIFO.
3.3.2 Address Matching
Ethernet addresses consist of two 6-byte fields. The first
bit of the address signifies whether it is a Station Address
or a Multicast/Broadcast Address.
First Bit
0
1
3.2.6 Detecting and Clearing a Transmit Retry
Condition
To enable the output drivers for the four TXRET pins, the
the TXINTEN input is driven low. Once a Tx retry condition
is detected, that port's internal Tx retry signal can be
cleared by first setting the RXTXPS[1:0] inputs to point to
that port. Then by driving the TXINTEN input low and then
pulsing the CLRTXERR input high for a minimum of one
RXRD_TXWR clock cycle, this will clear that port's TXRET
signal. The RXTXPS [1:0] and TXINTEN inputs must not
change during the high time of the CLRTXERR input.
Station Address: All destination address bytes must
match the corresponding bytes found in the Station
Address Register. If Group Address mode is enabled,
the last 4 bits of the station address are masked out
during address matching.
After computing the FCS on the first six bytes of the
address field (Destination address), a port uses bits 0
thru 5 as an address to its Multi-cast address filter
register. Bit 0 of the FCS is assumed to be where
receive data enters the FCS generation circuitry. If
the corresponding bit addressed in the Multicast address filter register is a ‘1’ the port will receive the
frame, otherwise it will discard the frame. Addressing
of the Multicast address filter register occurs using
bits 0 thru 2 to determine which byte is selected and
bits 3 thru 5 to determine which bit according to the
following tables:
FCS Bits
0 1 2
3.3.1 Preamble Processing
A port recognizes activity on the Ethernet via its Carrier
Sense line in 10 Mbit/sec Serial Mode or through its
Receive Data Valid line in MII mode. In 10 MBit/sec Serial
Mode the end of preamble is detected by a double 1 serial
receive data pattern preceded by 6 bits of alternating 1’s
and 0’s. In MII mode the end of preamble is recognized by
the following nibble pattern:
0
0
0
0
1
1
1
1
Logic Values
0 1
1 1
0 0
1 1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
Byte Selected
Byte 0
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5
Byte 6
Byte 7
FCS Bits
3 4 5
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
Bit Selected
Bit 0
Bit 1
Bit 2
Bit 3
Bit 4
Bit 5
Bit 6
Bit 7
Multicast Address: If the first bit of the incoming
address is a 1 and the port is programmed to accept
Multicast Addresses without using Hash filtering, the
frame is received. A port also can be programmed to
use the hash filter for determining acceptance of
multicast addresses.
In 10 MBit/sec Serial Mode, detection of a double 0 pattern
16 bit times after CSN goes high and before a proper Start
Frame Delimiter pattern is received will prevent reception
of the packet by the receiver. In MII mode, when RX_DV
goes high the RXD[3:0] lines must be driven with at least
1 byte of proper SFD pattern.
Broadcast Address: The six incoming destination
address bytes must all be FF hex. If a port is
programmed to accept Broadcast or Multicast Addresses the frame will be received.
18
4-18
MD400152/E
Station Address (Physical)
Multicast/Broadcast Address
(logical)
Address matching occurs as follows:
3.3 PACKET RECEPTION PER PORT
Each port within the chip continuously monitors the network. When activity is recognized via the Carrier Sense
(CSN) signal in 10 Mbit/sec Serial Mode, or through the
Receive Data Valid (RX_DV) signal in MII mode, the port
will then synchronize itself to the incoming data stream
through recognition of the Start Frame Delimiter (SFD) at
the end of Preamble. The destination address field of the
frame is then examined. Depending on the Address Match
Mode specified, the port will either recognize the frame as
being addressed to itself in a general or specific fashion or
abort the frame reception. The port can also be programmed to count all collisions on the network it's connected to.
RXD3
RXD2
RXD1
RXD0
Address
84C300A 4-Port
Fast Ethernet Controller
If the incoming frame is addressed to a port in the chip
specifically (Destination Address matches the contents of the Station Address Register), or is of general
or group interest (Broadcast or Multicast Address),
the port will pass the frame exclusive of Preamble and
FCS to the CPU buffer and indicate any error conditions at the end of the frame. If, however, the address
does not match, as soon as the mismatch is recognized, the port will terminate reception and issue an
RxDC.
This will enable the reception of any packet irrespective of
errors and also reduce the number of signals (RXDC1_4
and CLRRXERR) that need to be processed when the
corresponding RXABORT goes high.
3.3.5 Receive Discard Conditions
Receive packets can be discarded for not meeting the
minimum IEEE 802.3 requirements for a good packet, for
address mismatches when the chip is not in promiscuous
mode, and by either user intervention or symbol errors
occurring from a 100 Mbit/sec physical device. in the case
of discards due to oversized packets, address mismatches, or the assertion of the RXABORT pin during
packet reception, further writing of receive packet data to
the receive FIFO is halted once the mismatch, receive
abort or oversized packet condition is determined.
A port may be programmed via the Match Mode bits
of the Receive Command Register to ignore all
frames (Disable Receiver), accept all frames (Promiscuous mode), accept frames with the proper Station
Address or the Broadcast Address (Station/Broadcast), or accept all frames with the proper Station
Address, the Broadcast Address, or all Multicast
Addresses (Station/Broadcast/Multicast).
Except for discards due to address mismatches, all packet
discards occur after carrier sense, or Receive Data Valid
in MII mode, deasserts. The discarding of receive packets
for error conditions can be controlled through bits 0
through 3 of the receive command register, and through bit
4 of configuration register #2. Listed below are the
required conditions for a receive discard to be produced:
3.3.3 Terminating Reception
Reception is terminated when either of the following conditions occur:
Carrier Sense or Receive Data Valid Inactive:
Indicates that traffic is no longer present on the
Ethernet cable.
1. Bit 0 of the Rx command register is LOW and a
receive FIFO overflow occurred during reception.
Overflow: The host node for some reason is not able
to empty a port Receive FIFO as rapidly as it is filled,
and an error occurs as frame data is lost. On average
a port’s Receive FIFO must be serviced every 3200 ns
for 10 Mbit Ethernet or 320 ns for 100 Mbit Ethernet to
avoid this condition.
2. Bit 1 of the Rx command register is LOW and a
packet with a CRC error was received.
3.3.4 Using the RXABORT Pins to Terminate
Reception of a Packet
By pulsing the corresponding RXABORT pin high for a
minimum of 1 RXC cycle any time during the reception of
a packet, that particular port’s packet reception can be
terminated. When reception of a packet is terminated this
way, the Receive FIFO will be cleared and will stay cleared
until carrier sense in 10 MBit Serial Mode or Receive Data
Valid in MII mode, transitions from high to low or from low
to high indicating either the end of the packet being aborted
or the beginning of a new receive packet. It is important to
note that RXABORT will cause the RXDC pin to go high
based on the conditions described under “Conditions that
cause the RXDC pin to go high”.
5. Bit 4 of the Rx command register is LOW and a
packet of size greater than 1518 was received.
3. Bit 4 of Configuration register 2 is LOW and the
RXABORT pin is driven high while CSN is high.
4. Bit 3 of the Rx command register is LOW and a packet
with less than 64 bytes of data was received.
6. The Receiver is not in promiscuous mode and a
address mismatch occurs.
Discarding of a receive packet by a port will cause any
packet data that was written to that receive FIFO to be
flushed from the FIFO. If no completely received packets
are in the receive FIFO at the time a receive discard
occurs, the receive FIFO will be completely flushed of
data. If however, a completely received packet, as indicated by the packets status double word having been
written to the FIFO, is in the receive FIFO at the time of a
receive discard, the FIFO will be flushed only up to the last
completely received packet. To prevent a receive packet
from being discarded due to an error condition, you can
selectively enable the reception of errored packets as
described in the section describing bit settings on configuration register #2.
The RXDC signal is asserted so that an external processor
will always have an indication of a packet abortion irrespective of whether it’s aborted by the user or by an
external PHY. However, the assertion of the RXDC signal
can be avoided by setting bit 4 of configuration register #2.
4-19
19
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
Conditions that Cause the RXDC Pin to go HIGH
As packets are discarded due to the receive packet
error conditions given in section “3.3.5 Receive
Discard Conditions”, the corresponding port’s RXDC
pin may or may not assert. If a receive packet’s status
has been written to the receive FIFO and the packet’s
status has not yet been read from the FIFO, discards
caused by following packets with errors are handled
within the chip and the RXDC pin will not go HIGH. If
all status double words for all packets written to the
FIFO have been read out then the RXDC pin will go
HIGH under the following condition:
2. If there are no status double words in the receive
FIFO and if RXRDY goes HIGH just before a
discard condition occurs, RXRDY may go LOW
again before any FIFO reads have occurred.
This is due to the receive discard clearing the
FIFO of any receive bytes already written to the
FIFO. In this case, RXRDY is guaranteed to
remain HIGH for at least one RXRD_TXWR
clock cycle.
Detecting and Clearing a Receive Discard
Condition
To enable the output driver for the RXDC pins,
the RXINTEN input must be driven low. Once a
discard condition is detected, the receive discard can
be cleared by driving the RXINTEN input low and then
1. Enough of a receive packet has been written to
the FIFO to cause RXRDY to go HIGH before the
packet is discarded due to an error condition.
RXTXDATA0
RXTXDATA24
..
.
..
.
RXTXDATA7
PREAMBLE
RXTXDATA31
1ST BYTE
2ND BYTE
A0 . . . A7
A8 . . . A15
3RD BYTE
A16 . . . A23
RXTXDATA0
..
.
RXTXDATA7
4TH BYTE
5TH BYTE
6TH BYTE
A24 . . . A31
A32 . . . A39
A40 . . . A47
SOURCE ADDRESS . . .
DESTINATION ADDRESS
BITS WITHIN A DOUBLE WORD TRANSMITTED/RECEIVED BIT NO.“0” FIRST THROUGH BIT NO. “31” LAST.
Bit Serialization/Deserialization for Little Endian Format
RXTXDATA24
RXTXDATA0
..
.
..
.
RXTXDATA31
PREAMBLE
1ST BYTE
2ND BYTE
A0 . . . A7
A8 . . . A15
RXTXDATA7
3RD BYTE
A16 . . . A23
4TH BYTE
A24 . . . A31
RXTXDATA24
..
.
RXTXDATA31
5TH BYTE
6TH BYTE
A32 . . . A39
A40 . . . A47
DESTINATION ADDRESS
Bit Serialization/Deserialization for Big Endian Format
20
4-20
MD400152/E
SOURCE ADDRESS . . .
84C300A 4-Port
Fast Ethernet Controller
pulsing the CLRRXERR input high for a minimum of
one RXRD_TXWR clock cycle. The RXINTEN input
must not change state for the duration of the time that
the CLRRXERR input is high.
RXTXDATA bus first and least significant byte of the
RXTXDATA bus last. In Little Endian mode, the least
significant byte of each double word is transmitted first and
the most significant byte of each double word is transmitted last. On the receive side, if Big Endian mode is in effect
then the first data bytes received are assumed to be the
most significant bytes of the double word and appear on
the most significant portion of the RXTXDATA bus for
receive FIFO reads. The receiver reverses this order if the
chip is in Little Endian mode. The value of the BUSMODE
bit has no effect on the operation of the 84301 register
interface. It is important to note that the operation of the
byte enables remain the same for both modes.
Clearing Interrupts
Within one port, both receive and transmit interrupts
are combined into a single interrupt signal which then
goes to the INT output pin. The interrupt signal in the
chip is actually the result of the receive/transmit status
register outputs and the receive/transmit command
register interrupt enable bits that are set. To clear an
interrupt, the status that caused the interrupt needs to
be cleared. This can be accomplished by reading the
transmit status register and/or the receive status
register.
3.5.2 Transmit FIFO Interface
To determine if the transmit FIFO for any of the chips ports
has reached its threshold number of double words of
space available, all four TXRDY outputs can be enabled by
driving the TXINTEN input low. The TXRDY output for a
port will be high if there is enough space available in the
port's transmit FIFO to meet or exceed the programmed
threshold value.
3.4 SYSTEM INTERFACE
The chip system interface consists of one receive/transmit
32-bit bidirectional data bus, one 8-bit bidirectional command/status data bus, and each busses respective control
signals. Receive FIFO data is read and Transmit FIFO
data is written over the RXTXDATA[31:0] bus, and Command/Status data is written or read over the bidirectional
CDST[7:0] data bus.
Once one of the TXRDY outputs is determined to be high,
that port’s Transmit FIFO can be written. To write to a
port’s Transmit FIFO, the TXWREN and TXINTEN inputs
must be asserted low and at least one of the RXTXBE byte
enables must be low for each write cycle. The value of the
RXTXPS inputs determines which port is being written. All
of the above inputs are clocked into the chip on the high
going edge of the RXRD_TXWR clock input which also
acts as the FIFO write strobe. Because of this pipe lining
the actual FIFO write will occur one RXRD_TXWR cycle
after the assertion of the Transmit FIFO interface control
3.5 FIFO INTERFACE
3.5.1 Little Endian and Big Endian Format
The FIFO interface control includes the BUSMODE bit 7 in
configuration register #2, which sets the 84C300A FIFO
interface to Big Endian or Little Endian byte transmit/
receive data order. In Big Endian mode, data written to the
transmit FIFO is transmitted most significant byte of the
4-21
21
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
signals. Valid combinations of the RXTXBE inputs for
transmit FIFO writes are given below:
writing of a packet to the Transmit FIFO, it will not go
HIGH again until both of the following conditions are
true:
RXTXBE3 RXTXBE2 RXTXBE1 RXTXBE0
0
0
0
0
1
0
0
0
0
0
0
1
1
1
0
0
1
0
0
1
0
0
1
1
1
1
1
0
1
1
0
1
1
0
1
1
0
1
1
1
1. The packet has been completely transmitted or
to a point 64 byte times from the beginning of the
transmission has been reached.
2. The number of bytes taken out of the transmit
FIFO for transmission subtracted from the
number of bytes written to the FIFO leaves the
FIFO with enough double word space avail
able to meet the threshold setting.
It is important to note that until the packet is completely transmitted or until enough of the packet is
transmitted to get past the normal collision window,
the TXRDY output will only reflect how many writes
have occurred and will not reflect how much of the
FIFO data has been read out for transmission. Because of this, it is important to insure enough packet
data has been written to prevent FIFO underflows if
there exists a large latency between the TXRDY
output being determined HIGH and the writing of more
data to the FIFO.
The TXRDY output for the port being read will remain high
until the port's transmit FIFO no longer has enough double
word space to meet the programmed threshold value.
The transmit and the receive FIFO are 128 bytes deep
organized as double word (32 bits) rows. During writes to
the transmit FIFO, the FIFO pointer gets incremented on
every write to the FIFO, irrespective of whether all the four
byte enables are asserted or not. Hence, during non
double word writes to the FIFO, one entire row of the FIFO
gets filled irrespective of whether all the bytes are valid or
not. The 84C300A automatically ignores the invalid bytes
when the data gets transmitted from the FIFO.
3.5.3 Receive FIFO Interface
To determine if the receive FIFO has reached its threshold
number of double words of data, the RXRDY output can be
enabled by driving the RXINTEN input low. The RXRDY
output for the chip will be high under one of the following
conditions:
1. There are enough double words of data in the
channel's receive FIFO to meet or exceed the
programmed threshold value.
While transmit FIFO writes are occurring the SPDTAVL
output will remain high until the highgoing edge of the write
to the second to the last remaining double word space in
the FIFO. Because transmit FIFO writes are pipelined,
there will always be one more internal FIFO write after
TXWREN is deasserted.
2. The status double word for a receive packet with
an end of frame value of HIGH is in the receive FIFO.
Once the RXRDY output is determined to be high, the
receive FIFO can be read. To read from the Receive FIFO,
the RXRDEN and RXINTEN inputs must be asserted low
and the RXTXBE byte enables must be low for each read
cycle. Similar to the Transmit FIFO interface, all of the
above Receive FIFO interface control signals are clocked
into the chip on the high going edge of the RXRD_TXWR
clock input which also acts as the FIFO read strobe.
Because of this pipe lining the actual FIFO read will occur
one RXRD_TXWR cycle after the assertion of the Receive
FIFO interface control signals.
Effect of Auto Retransmission Upon TXRDY
Behavior
As a packet is read out of a port’s Transmit FIFO by the
transmitter for transmission onto the network, the
corresponding TXRDY signal will not reflect any
reads that have occurred to the FIFO until enough
bytes of data have been transmitted to get past the
normal collision window of less than 64 byte times.
This means that if a port’s TXRDY goes low during the
22
4-22
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
3.5.4 Special Conditions on the RXRD_TXWR input
This input is required to be tied to a continuous clock signal
whose maximum clock frequency can be 33Mhz. The
number of read or write cycles occurring to the chip is
controlled through the TXWREN and RXRDEN inputs. All
transitions of the TXRDY, RXRDY, RXTXEOF, SPDTAVL,
RXDC, RXTXDATA[31:0], and TXRET outputs are synchronized internally to the RXRD_TXWR clock and are
clocked to the output drivers on the highgoing edge of the
clock.
Depending on the way RXRDEN is used, two different
modes are possible, when the chip is used in the nonbidirectional byte enable mode.
On burst reads (RXRDEN being asserted for multiple clock
cycles), if the first read is not a double word read, the
second read will always increment the FIFO pointer irrespective of whether all the byte enables are enabled or not.
In this mode, 16 bit reads are possible by muxing the LSB
and the MSB of the data bus. 8 bit reads are not possible.
On single reads (RXRDEN being asserted for only one
clock cycle), the FIFO pointer will get incremented only on
a double word read. In this mode, the different bytes of the
data bus can be muxed to perform multiple 8 bit or 16 bit
reads. But, all the reads of the bytes belonging to one row
should be terminated with a double word read to increment
the FIFO pointer.
3.6 REGISTER INTERFACE
3.6.1 Internal Port Register Addressing Table
Writing of Command, Configuration, and Station Address
registers and reading of status registers is controlled by
the ENREGIO, RD, WR, REGPS[1:0], and A[3:0] signals.
The ENREGIO signal is used as a general register interface enable and must be active low before any register
operations can occur. The REGPS signals are used to
select which port’s registers are to be accessed. The
A[3:0] are used to address which register within a port is
being accessed. Initiation of a register read is controlled by
the RD signal and initiation of a register write is controlled
by the WR signal. A port’s registers may be accessed at
any time. However, it is recommended that writing to the
command register, be done only during interframe gaps.
When the chip is being read, the RXRDY output will remain
high until the high going edge of the read that results in one
of the following conditions:
1. The FIFO no longer has enough data to meet the
threshold setting.
2. A packet’s status double word with its associated
HIGH end of frame value is read out.
With the exception of the two Match Mode bits in the
Receive Command Register, all bits in both command
registers are interrupt enable bits. Changing the interrupt
enable bits during frame transmission does not affect the
frame integrity. Asynchronous error events, however,
e.g., overflow, underflow, etc., may cause chip operation
to vary, if their corresponding enable bits are being altered
at the same time.
In the case of RXRDY being driven LOW upon condition
two given above, it will remain LOW for 8 RXRD_TXWR
clock cycles and then goes back HIGH if one of the
conditions for RXRDY being HIGH is met.
During reads from the FIFO, the SPDTAVL output will
remain high until the high going edge of the RXRD_TXWR
of the read that causes one of the following conditions to
occur:
Reading the status registers may also occur at any time
during transmission or reception.
1. The read that empties the FIFO completely.
Status Registers and all management counters are read
only registers. The Rx and Tx Command Registers are
write only or read/write registers based on the address
inputs. Please refer to the mode/port select table for
details. All other registers are writable and readable.
Access to these registers is via the CPU interface: Control
signals ENREGIO, RD, WR , REGPS [1:0] A[3:0], and the
Command/Status Data Bus CDST [7:0].
2. The read that reads a packets status double word
from the FIFO.
When one of the above conditions is met and SPDTAVL is
driven low upon the high going edge of the RXRD_TXWR,
the SPDTAVL output will remain low for a period of 8
RXRD_TXWR clock cycles. For the time that SPDTAVL
remains low, further reads are blocked within the chip even
if external reads continue. This allows overreading the
receive FIFO by a few cycles without, internal to the chip,
reading an empty FIFO or reading new packet data before
the present packet is processed. It is up to the processor
doing the FIFO reads to determine on which read cycle the
SPDTAVL went low and thereby which read cycles are
over reads containing invalid data.
3.6.2 Station Address Register
The Station Address Register is 6 bytes in length. The
contents may be written in any order, with bit “0” of byte “0”
corresponding to the first bit received in the data stream,
4-23
23
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
3.6.1 Internal Port Register Addressing Table
Transmit
Command
Register Register
Bits
Address
Register Description
6
0
0
0
0
0
0
5
0
0
0
0
0
0
A3
0
0
0
0
0
0
A2 A1
0
0
0
0
0
1
0
1
1
0
1
0
X
X
X
X
0
0
1
1
1
1
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
0
0
1
1
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
X
X
1
A0
0
1
0
1
0
1
Read
Station Address 0
Station Address 1
Station Address 2
Station Address 3
Station Address 4
Station Address 5
Write
Station Address 0
Station Address 1
Station Address 2
Station Address 3
Station Address 4
Station Address 5
0
1
Rx Status Register
Tx Status Register
Rx Command Register
Tx Command Register
0
0
1
1
0
0
0
0
0
1
0
1
0
1
0
1
Hash Register 0
Hash Register 1
Hash Register 2
Hash Register 3
Hash Register 4
Hash Register 5
Hash Register 6
Hash Register 7
Hash Register 0
Hash Register 1
Hash Register 2
Hash Register 3
Hash Register 4
Hash Register 5
Hash Register 6
Hash Register 7
0
0
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
0
0
0
1
0
1
0
1
0
1
0
1
FIFO Threshold Register
Configuration Register #2
Configuration Register #1
Defer Count Register
CRC Error Counter
Runt Frame Counter
Oversize Frame Counter
Alignment Error Counter
Tx Collision Counter
Rx Collision Counter
FIFO Threshold Register
Configuration Register #2
Configuration Register #1
Defer Count Register
—
—
—
—
—
—
0
0
0
Transmit Control/Product
I.D. Register
Transmit Control/Product
I.D. Register[1]
Note: 1. The upper four bits are read only.
24
4-24
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
and indicating whether the address is physical or logical.
Bit 7 of station address byte 5 is compared to the last bit of
the received destination address. The Station Address
should be programmed prior to enabling a port’s receiver.
1. A Transmit FIFO underflow occurred while
transmitting the packet.
2. A collision occurred while transmitting the packet.
3. A transmit error condition occurred i.e,
(Carrier sense never went active during
transmission or went from an active to inactive state
during transmission or 16 collisions occurred for a
transmit packet or a late collision occurred).
3.6.3 Transmit Command Register
The transmit command register is an 8 bit register. Bits 0
through 3 of the Transmit Command Register function as
interrupt mask bits, which provide for control of the conditions allowed to generate transmit interrupts. Each of the
four bits may be individually set or cleared. When set, the
occurrence of the associated condition will cause an
interrupt to be generated. The four specific conditions for
which interrupts may be generated are:
4. The packet was transmitted successfully.
Interrupts are cleared by following the procedure given in
the section entitled "Clearing Interrupts" in section 3.3.5.
Transmit Command Register Format
7
6
Bit
Value
0
‘1’
1
5
4
3
2
1
Definition
0
R/W
Default Values
After Reset
Generates an interrupt on the
occurrence of a transmit underflow.
W
0
‘1’
Generates an interrupt on the
occurrence of a collision during
the transmission of a packet.
W
0
2
‘1’
Generates an interrupt on the
occurrence of a transmit error
condition.
W
0
3
‘1’
Generates an interrupt on the
occurrence of a successful
transmission.
W
0
4
‘1’
Sets the chip into the MII mode
W
0
5
‘1’
Register
Code Bit
0.
W
0
6
‘1’
Register
Code Bit
1.
W
0
7
‘0’
Test Mode.
Note: This bit should not be
written HIGH under normal
circumstances.
W
0
These two bits are
used in conjunction
with the A[3:0]
address pins to access
registers other than the
Receive and Transmit
command registers
within a port.
4-25
25
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
3.6.4 Transmit Status Register
Within each port's transmit section are 2 transmit status
registers. These registers give the appearance of a single
register to an external CPU. With each transmission attempt, whether successful or not, one of the status registers is written with the transmit status for that packet and
bit 7 of that register is set to a 0 until both registers are full.
When both registers are full, no new transmit status can be
written until one of the registers is read. To an external
CPU, both transmit status registers appear as a single
register. If the CPU reads a LOW value for bit 7 of the
transmit status register, this indicates that either one or
both of the internal transmit registers contains new status.
A delay time after the highgoing edge of the read operation
that reads new transmit status, one of the internal transmit
status registers will be cleared and made available for new
transmit status. Following are the types of transmit status
given through status register:
A port can be programmed so that if both transmit registers
are full, no new transmissions will occur until at least one
of the register is cleared by reading it. To program this
feature, bit #1 of configuration register #2 needs to be
written to a 1 value.
Also a port can be programmed so that no new transmit
status is loaded if the transmission is successful.
Transmit Status Register Format
7
6
Bit
Value
0
‘1’
1
5
4
3
2
1
Definition
0
R/W
Value After
Reset
Indicates the occurrence of a
Transmit FIFO underflow.
R
0
‘1’
Indicates the occurrence of a
collision during a transmission
attempt.
R
0
2
‘1’
Indicates that 16 collisions
occurred while attempting to
transmit a packet.
R
0
3
‘1’
Indicates the successful
completion of a packet
tranmission.
R
0
4
‘1’
Indicates the occurrence of a
carrier sense error during a
transmission attempt.
R
0
5
‘1’
Indicates the occurrence of a
deferred transmission due to
carrier sense being detected HIGH.
R
0
6
‘1’
Indicates the occurrence of a late
collision. Late collision is the
occurrence of a transmit collision
64 byte times after TXEN went
HIGH.
R
0
7
‘1’
Indicates old/new status.
R
0
26
4-26
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
3.6.5 Receive Command Register
A port’s Receive Command Register has two primary
functions, it specifies the Address Match Mode, and it
specifies which types of receive frames will be received
and if an associated interrupt will be produced. To set
interrupt conditions the Receive Command Register uses
bits 5 through 0 in conjunction with bit #7 of configuration
register #1.
interrupt conditions even if one of the bits 0 through 5 in the
receive command register is set HIGH. This allows enabling reception of receive packets with errors without an
interrupt being produced. With the general receive interrupt bit LOW, a receive interrupt can be produced on one
or more of the following conditions by setting its associated
interrupt enable bit in the receive command register:
Bit 7 of configuration register #1 is a general receive
interrupt disable. Setting this bit HIGH disables all receive
Receive Command Register Format
7
6
Receive
Command
Register
Bit 0
5
Receive
Command
Register
Values
4
3
2
1
0
Definition
R/W
Default
Values
Upon Reset
1
Enables Reception of packets with a receive overflow error
without generating an RXDC. If Bit 7 of Configuration
Register #1 is ‘0’, receive overflow error will assert interrupt
if this bit is ‘1’.
W
0
0
Automatically discards packets with a receive overflow error
by generating an RXDC.
W
0
1
Enables Reception of packets with a receive CRC error
without generating an RXDC. If Bit 7 of Configuration
Register #1 is ‘0’, receive CRC error will assert interrupt
if this bit is ‘1’.
W
0
0
Automatically discards packets with a receive CRC error by
generating an RXDC.
W
0
1
Enables Reception of oversized packets without generating
an RXDC. If Bit 7 of Configuration Register #1 is ‘0’,
oversized receive packet will assert interrupt if this bit is ‘1’.
W
0
0
Automatically discards oversized receive packets by
generating an RXDC.
W
0
1
Enables Reception of undersized packets without generating
an RXDC. If Bit 7 of Configuration Register #1 is ‘0’,
undersized receive packet will assert interrupt if this bit is ‘1’.
W
0
0
Automatically discards undersized receive packets by
generating an RXDC.
W
0
Bit 4
1
If Bit 7 of Configuration Register #1 is ‘0’, setting this bit to ‘1’
asserts interrupt as an indication of the first 12 bytes received.
W
0
Bit 5
1
If Bit 7 of Configuration Register #1 is ‘0’, setting this bit to ‘1’
asserts interrupt as an indication of the reception of a good
packet for debugging purposes.
W
0
Bit 1
Bit 2
Bit 3
Bit 6
Match mode 0.
Please refer to the following table for match mode definitions.
Bit 7
Match mode 1.
Please refer to the following table for match mode definitions.
4-27
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MD400152/E
84C300A 4-Port
Fast Ethernet Controller
Match
Mode
1
Match
Mode
0
0
0
0
Receiver Disable
1
0
1
Receive All Frames
2
1
0
Receive Station or Broadcast
Frames
3
1
1
Receive Station,
Broadcast/Multicast Frames
3.6.6 Receive Status Register
Within each port’s receive section there is a receive status
register that is written with the status of each receive
packet whether it is discarded or not. Once the receive
status register is written, bit 7 of the register is set to a 0 and
the register is write protected from being overwritten with
new status until it is read. Reading the receive status
register clears the register and enables it to be written with
new status. The following packet status is reported in the
receive status register:
Function
NOTE
Changing the receive Match Mode bits during frame reception may change chip operation and give unpredictable
results.
Receive Status Register Format
7
6
Bit
Value
0
‘1’
1
5
4
3
2
1
Definition
0
R/W
Default
Indicates that a frame with an
overflow error has been received.
R
0
‘1’
Indicates that a frame with a CRC
error has been received.
R
0
2
‘1’
Indicates that a frame with dribble
bits or nibbles has been received.
R
0
3
‘1’
Indicates that a short frame has
been received.
R
0
4
‘1’
Indicates that an oversized frame
has been received.
R
0
5
‘1’
Indicates that a good frame has
been received.
R
0
6
‘1’
Indicates that the first 12 bytes of
a frame has been received.
R
0
7
‘1/0’
Indicates old (1) /new (0) status
R
0
28
4-28
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
Receive packet status is also included as part of the final
double word of receive data for a packet that is not
discarded. The final double word of a packet as read from
the receive FIFO contains the status and the byte count for
that packet with the status appearing as the least significant word of the double word and the byte count appearing
in the two most significant bytes of the double word. The
status read through the FIFO has the same bit values as
the receive status register except for the following:
This type of error can only be caused by some type of noise
glitch or other unusual occurrence within the receive
section. Any packet read from the FIFO with Bit 8 of the
status set HIGH should be considered to have bad data.
This condition should never occur in a properly designed
application. If status is ever read with Bit 8 being HIGH, the
receive section will automatically reset itself to provide a
clean starting point for further packet reception.
Clearing Interrupts
Both receive and transmit interrupts for a port are
combined into a single interrupt signal which then
goes to that port's INT output pin. The interrupt signal
within a port in the chip is actually the result of the
receive/transmit status register outputs and the receive/transmit command register interrupt enable bits
that are set. To clear an interrupt the status that
caused the interrupt needs to be cleared. This can be
accomplished by reading the transmit status register
and/or the receive status register.
Bit 7: RXABORT During Reception
Bit 8: Read Error Condition
Bit 7 is an indication that the RXABORT pin was pulsed
HIGH while CSN was HIGH for the packet. Bit 8 Indicates
that some type of error has occurred in the receive FIFO
control circuitry with a result that the number of double
words written to the FIFO as indicated by the byte count
portion of the status double word does not equal the
number of double words read from the FIFO for the packet.
3.6.7 Configuration Registers
The Status Double Word Format
31
16
8
0
Reserved
Byte Count
Status Register Word
Note: This status double word gets appended to the packet in
the same format for both Little and Big Endian modes.
Configuration Register #1
Allows for control of a port’s various transmit and receive
features. Set to all 0’s after reset.
Mode A: Group Address Mode
In this mode the last 4 bits of the serial receive data
stream for the destination address are masked out in
address comparison. This means that when the
destination address is compared against the value
Configuration Register #1
7
6
5
4
3
2
1
Bit
Value
0
‘1’
Enables Group Address Mode.
‘0’
Disables Group Address Mode.
‘1’
Detection of a 2.5 MHz TXCLK
from the Transceiver.
‘0’
Detection of a 25 MHz TXCLK from
the Transceiver
1
‘1’
2
Definition
0
R/W
Default
Mode
W only
0
A
R only
0
Enables Transmit packet
Autopad Mode.
R/W
0
B
‘1’
Enables transmit no preamble
mode.
R/W
0
C
3
‘1’
Refer to TABLE A
R/W
0
4
‘1’
Enables transmit no CRC mode.
R/W
0
5
‘1’
Refer to TABLE A
R/W
0
6
‘1’
Enables Receive CRC Mode.
R/W
0
G
7
‘1’
Disables Receive Interrupts
R/W
0
H
4-29
29
MD400152/E
E
84C300A 4-Port
Fast Ethernet Controller
programmed in the station address register that the
packet will not be rejected due to incorrect address
even its last 4 bits did not match.
Mode E: Transmit No CRC Mode
This mode prevents a port’s transmitter from appending transmit data with an FCS.
Mode B: Transmit Packet Autopad Mode
This feature automatically pads packets to be transmitted with less than 60 bytes of data out to a minimum
IEEE 802.3 standard packet length of 60 bytes excluding FCS. Padding is done with bytes of 00 hex in
10 Mbit/sec Serial Mode and 55 hex in MII mode.
Mode G: Receive CRC Mode
In this mode a ports receiver loads the 4 bytes of FCS
into the receive FIFO along with the data allowing the
FCS value to be read out.
Mode H: Disable Receive Interrupts
With this bit set a ports receiver is disabled from
producing receive interrupts.
Mode C: Transmit No Preamble Mode
This mode prevents the transmitter from adding a
preamble pattern at the beginning of data to be
transmitted.
Full Duplex/Half Duplex Modes
Operation with Receive Own Transmit Disable. TABLE A
The following description assumes that a transceiver
is connected to the MAC.
Bit 3
Bit 5
‘OR’ FDUPLX
Pin*
Mode
Functional Description
1
0
(Default)
Half
Duplex
In this mode the transmit data looped back from the transceiver is ignored
by the controller. The data does not get written into the receive FIFO and
the Rxrdy does not reflect the incoming data.
0
1
(Default)
Full
Duplex
In this mode the transceiver (In Full Duplex mode) will not loopback the
transmitted data. However, since data reception is possible during
transmission, bit 3 should be written with ‘0’ so that the data gets written
to the Receive FIFO.
0
0
(Default) (Default)
Loopback
Mode
In normal Half Duplex operation the PHY loops back the transmitted data
back to the MAC. In other words, the PHY always loops back the
transmitted data in half duplex mode. As far as the controller is concerned,
it knows that the data coming back is it’s own transmitted packet and since
bit 3 is not set, the transmitted packet gets written into the receive FIFO.
1
1
Reserved
Note: There is no internal loopback within the MAC. Loopback is dependent on a PHY
connected to the MAC.
* The software bit setting and the hardware setting (pin #123, 124, 125 or 127) have an OR
relationship. This means that either the hardware or software setting will enable Full Duplex.
30
4-30
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
Configuration Register #2
Allows for control of a port’s transmission of one packet at
a time, Busmode, Multi-cast hash filter, reception of runt
frames, and halting new transmissions until one of the
port’s transmit status registers is cleared.
transmissions will occur until one of the Tx Status
Registers is cleared, even if the transmit FIFO has
transmit data.
Mode C: EOF on Data
This function puts a HIGH EOF value on both the last
double word of data and the status double word.
Mode A: Don’t Load Tx Status Upon Successful
Transmit Mode
If bit #0 of configuration register #2 is set, then a
packet that has been transmitted successfully will not
have it’s status loaded into either of the two internal
transmit status registers.
Mode D: Multicast Mode
Each port has a 64 bit multicast address filter register
which can be accessed as shown in the Internal Port
Register Addressing Table 3.6.1 on page 23. When
a port is programmed to receive multicast frames
(match mode 3), after computing the CRC on the
address field of the receiving frame (first 6 bytes), it
Mode B: Disable Further Transmission Upon Full
Tx Status Register Mode
If bit #1 of configuration register #2 is set, whenever
both Tx Status Registers have been filled, no new
Configuration Register #2
7
6
Bit
Value
0
5
4
3
2
1
0
Definition
R/W
Default
Mode
‘1’
Disables loads to the transmit
status register upon a successful
transmission.
R/W
0
A
1
‘1’
Disables new transmissions upon a
full transmit status register condition.
R/W
0
B
2
‘1’
Generates an EOF on both the last
double word of data and also the
status double word.
R/W
0
C
3
‘1’
Enables the hash filter for
multicast operation.
R/W
0
D
4
‘1’
Enables the reception of packets
without a discard even if the
RXABORTgoes high during the
reception of a packet.
R/W
0
E
5[3]
‘1’
Packs only two bytes
into the first double
word written to the
Receive FIFO.[1]
W only
0
F1
‘0’
Normal mode.[2]
‘1’
SQE Test Pass
R only
0
F2
‘0’
SQE Test Fail[4]
6
‘1’
When this bit is SET, the TXRDY
is driven low after an EOF is
written into the transmit FIFO and
stays low until the packet is
successfully transmitted.
R/W
0
G
7
‘1’
Sets the chip into Big Endian Mode
R/W
0
H
Notes: 1. Non-Bidirectional Byte Enable Mode only.
2. Must be used for Bidirectional Byte Enable Mode.
3. This bit address is shared for two functions.
4. Read will clear this bit to ‘0’.
4-31
31
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
will index to the multicast address filter register depending on bits 0 to 5 of the CRC. If the corresponding
bit is a ‘1’ it will receive the frame, otherwise it will
discard the frame.
Mode G: Successful Packet Transmission Complete Feature
This feature is programmable by setting bit 6 of
configuration register #2 to a ‘1’ value. If this bit is set,
then, independent of the FIFO threshold setting, the
corresponding port’s TXRDY pin will go LOW once
the final double word of data for a transmit packet is
written to the transmit FIFO. Once a port’s TXRDY
has been driven LOW due to this condition, it will
remain LOW until the packet has completed transmission without error or until a transmission exception
condition causing the TXRET pin to go HIGH is
cleared. This allows the user to determine when a
packet has completed successful transmission by
detecting when the corresponding port’s TXRDY
goes HIGH after the final double word of the packet
has been written. After TXRDY goes LOW due to a
double word write with the RXTXEOF pin HIGH,
further writes to the transmit FIFO are allowed as long
as the SPDTAVL pin indicates that there is still space
available within the transmit FIFO.
Mode E: Receive Without Discard Mode
When this bit is written “High”, packets will be received
without discarding even if the RXABORT goes high
during reception.
Mode F1/F2: Pack Only Two Valid Bytes in First
Receive Double Word/SQE Status, Bit 5
Mode F1: When this bit is written HIGH, the first
double word of data written to the receive FIFO for a
receive packet will have only two valid bytes. When
this first double word is read out of the receive FIFO,
which two bytes are valid depends on whether the port
has been programmed for Big Endian or Little Endian
data formats. Thus, if bit 7 of Configuration Register
#2 (Endianess selection) is set HIGH (Big Endian),
RXTXDATA[15:0] will be valid for the first double word
read; if bit 7 is set LOW (Little Endian),
RXTXDATA[31:16] will be valid. All subsequent
double words of data read from the receive FIFO will
contain 4 valid bytes except for the last double word
which may not have all 4 bytes valid.
Mode H: Big Endian Mode
Writing this bit HIGH programs the port to Big Endian
mode.
Mode F2: Reading this bit provides SQE test results.
The SQE function is always on; reading this register
causes an automatic reset of this bit value to “zero”.
32
4-32
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
3.6.8 FIFO Threshold Register
This register allows programming of the threshold of
Space Available and/or Data Available double word
counts that cause assertion of the TxRDY and/or RxRDY
signals respectively. Bits 4 through 7, when written with a
binary value, indicates the minimum number of double
words necessary in the receive FIFO before RxRDY is
asserted. Similarly, bits 0 through 3, when written with a
binary value, indicate the minimum number of double word
wide spaces necessary in the transmit FIFO for TxRDY to
be asserted. Table 3.6.8.1 shows how many double
words of space/data are required to cause the TXRDY/
RXRDY signals to go high for each threshold setting.
defer time. The defer time calculated by the following
algorithms are for the first 2/3 of the defer period only. For
further details, please refer to the section 3.2.2.
Algorithm for Defer Time Calculations for MII
Defer Time = Int {{ Int (Delay /40) + 5 + DefRegSet}/2} + 2
Defer Time = The transmit defer time in byte times
Delay = Delay from the falling edge of TXEN to the falling
edge of CSN. (Half Duplex)
= 0 (Full Duplex)
DefRegSet = The transmit defer register setting
3.6.9 Defer Register Calculations for the 84C300A
Int = Using the Whole Number Portion
Defer Time Definitions
In the standard Half Duplex Mode, Defer time is defined as
the time from the falling edge of carrier sense to the rising
edge of TXEN. In full duplex mode, the defer time is
measured as the time from the falling edge of TXEN to the
next rising edge of TXEN. The binary value programmed
into the defer count register is used to determine how many
byte times the defer time will be set to. The algorithms
below illustrates how the defer time is calculated.
Example Calculations
To find out the value that needs to be programmed into the
defer register for a defer time of 960 ns, the following steps
need to be taken
Assume Delay = 340 ns
Desired Defer Time = 960 ns = 12 byte times
Note: The desired defer time should be a multiple
of 80
The defer time is split into two periods. The first period is
the first 2/3 and the second period is the second 1/3 of the
3.6.8.1 FIFO Threshold Register Settings Table
Fifo Threshold Register Bits
Minimum # of
Double Words of
Data for RXRDY High
Minimum # of
Double Word Spaces
for TXRDY High
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
1
1
0
0
0
1
0
0
0
1
2
2
0
0
1
0
0
0
1
0
3
3
0
0
1
1
0
0
1
1
4
4
0
1
0
0
0
1
0
0
5
5
0
1
0
1
0
1
0
1
6
6
0
1
1
0
0
1
1
0
7
7
0
1
1
1
0
1
1
1
8
8
1
0
0
0
1
0
0
0
9
9
1
0
0
1
1
0
0
1
10
10
1
0
1
0
1
0
1
0
11
11
1
0
1
1
1
0
1
1
12
12
1
1
0
0
1
1
0
0
13
13
1
1
0
1
1
1
0
1
14
14
1
1
1
0
1
1
1
0
15
15
1
1
1
1
1
1
1
1
16
16
4-33
33
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
Step 1: Calculation of the Actual Defer Time
Step 1: Calculation of the Actual Defer Time
Let’s assume a Defer Register Setting Value of 10
Let’s assume a Defer Register Setting Value of 21
Defer Time = Int{ {Int (Delay / 40) + 5 + DefRegSet}
/2} + 2
Defer Time = Int { { Int (Delay / 100) + 17 + DefRegSet}
/8} + 2
= Int { { Int ( 8.5 ) + 5 + 10 }/2} + 2
= Int { { Int (34) + 17 + 21}/8} + 2
= Int { 11.5 } + 2
= Int {9} + 2
= 11 + 2 = 13 byte times
= 9 + 2 = 11 byte times
Step 2: Calculation of the Actual Defer
Register Setting
Step 2: Calculation of the Actual Defer Register
Setting
Since we know that the value derived from the
previous step is 1 byte time greater than what
is desired we will decrement the assumed
defer register setting by 3 and do the
calculations again.
Since we know that the value derived from the
previous step is 1 byte time lower than what is
desired we will increment the assumed defer
register setting by 8 and do the calculations again.
Let’s assume a Defer Register Setting Value of 7
Let’s assume a Defer Register Setting Value of 29
Defer Time = Int { {Int(Delay/40) + 5 + DefRegSet}
/2} + 2
Defer Time = Int {{Int (Delay / 100)+17+DefRegSet}
/8} + 2
= Int { { Int( 8.5 ) + 5 + 7 } /2 } + 2
= Int { { Int (34) + 17 + 29 } /8} + 2
= Int { 10 } + 2
= Int { 10 } + 2
= 12 byte times
= 10 + 2 = 12 byte times
Note: Please note that you might have to do this process
several times before you can get the actual defer register
setting for a desired defer time based on your delays.
Please note that you might have to do this process
several times before you can get the actual defer
register setting for a desired defer time based on your
delays.
Algorithm for Defer Time Calculations for 10 Mbit
Serial Mode
3.6.10 Transmit Control/Product I.D. Register
The lower four bits can be used to set a threshold value on
the transmit FIFO that can be used to control the packet
transmission and the upper four bits of this register contains the product I.D. When the lower four bits are written
with a decimal value ranging from 1 to 15, packet transmission from the FIFO will begin only when the count of the
double words of data written into the transmit FIFO equals
or exceeds twice the register value. For example, when
the lower four bits are written with a decimal value of 15,
data transmission will begin only after the FIFO is written
with 30 or more double words of data. This threshold value
is valid only at the beginning of frame transmission and it
will take effect again when the user starts to load the
beginning of the next frame. The default decimal value of
the lower four bits is ‘0’ and packet transmission will begin
automatically when the FIFO is loaded with a minimum of
one double word of data. The upper four bits are read only
and contain a value of ‘A’, ‘B’, or ‘C’, depending on the die
revision.
Defer Time = Int {{Int (Delay/100)+17+DefRegSet}/8}+2
Defer Time = The transmit defer time in byte times
Delay = Delay from the down going edge of TXEN to the
down going edge of CSN. (Half Duplex)
= 0 (Full Duplex)
DefRegSet = The transmit defer register setting
Int = Using the Whole Number Portion
Example Calculations
To find out the value that needs to be programmed
into the defer register for a defer time of 9600 ns, the
following steps need to be taken
Assume Delay = 3400 ns
Desired Defer Time = 9600 ns = 12 byte times
The desired byte times should be a multiple of 800
34
4-34
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
high byte followed by the second, that will read out the low
byte. Upon reading the high byte, the count value of the low
byte is frozen to prevent the low byte count value from
rolling over before it is read. Normally, once the low byte
has been read the counter is reset to zero. Should the
84C300A attempt to increment the counter while it is
frozen, then reading the low byte of the counter causes it
to be loaded with 0001 hex thereby preventing the counter
from missing a count.
3.7 COUNTERS
CRC Error Counter
This is a 16 bit read only counter that counts the number
of frames received or discarded with CRC errors but no
framing errors. Upon reaching its maximum count value of
FFFF hex, this counter will stop counting. To read this
counter, two consecutive reads need to be performed to
the same address location. The first read, reads out the
high byte followed by the second, that will read out the low
byte. Upon reading the high byte, the count value of the low
byte is frozen to prevent the low byte count value from
rolling over before it is read. Normally, once the low byte
has been read the counter is reset to zero. Should the
84C300A attempt to increment the counter while it is
frozen, then reading the low byte of the counter causes it
to be loaded with 0001 hex thereby preventing the counter
from missing a count.
Transmit Collision Counter
This is a 16 bit read only counter. Bits 15 through 11 of this
counter count the number of retransmission attempts a
packet required before being transmitted successfully.
Bits 10 through 0 count the number of transmit collisions a
port has experienced. Upon reaching its maximum count
value of FFFF hex, this counter will stop counting. To read
this counter, two consecutive reads need to be performed
to the same address location. The first read, reads out the
high byte followed by the second, that will read out the low
byte. Upon reading the high byte, the count value of the low
byte is frozen to prevent the low byte count value from
rolling over before it is read. Normally, once the low byte
has been read the counter is reset to zero. Should the
84C300A attempt to increment the counter while it is
frozen, then reading the low byte of the counter causes it
to be loaded with 0001 hex thereby preventing the counter
from missing a count.
Runt Frame Counter
This is a 16 bit read only counter that counts the number
of frames received or discarded less than the minimum
valid frame time (64 bytes). Upon reaching its maximum
count value of FFFF hex, this counter will stop counting. To
read this counter, two consecutive reads need to be
performed to the same address location. The first read,
reads out the high byte followed by the second, that will
read out the low byte. Upon reading the high byte, the
count value of the low byte is frozen to prevent the low byte
count value from rolling over before it is read. Normally,
once the low byte has been read the counter is reset to
zero. Should the 84C300A attempt to increment the
counter while it is frozen, then reading the low byte of the
counter causes it to be loaded with 0001 hex thereby
preventing the counter from missing a count.
Receive Collision Counter
This is a 16 bit read only counter that counts the number
of collisions other than transmit collisions. All the receive
collisions counted should occur beyond the SQE test
window. It is important to note that this counter gets
incremented only when the collision input is asserted by
the PHY device when the MAC device is not transmitting
data. Upon reaching its maximum count value of FFFF
hex, this counter will stop counting. To read this counter,
two consecutive reads need to be performed to the same
address location. The first read, reads out the high byte
followed by the second, that will read out the low byte.
Upon reading the high byte, the count value of the low byte
is frozen to prevent the low byte count value from rolling
over before it is read. Normally, once the low byte has been
read the counter is reset to zero. Should the 84C300A
attempt to increment the counter while it is frozen, then
reading the low byte of the counter causes it to be loaded
with 0001 hex thereby preventing the counter from missing
a count.
Receive Oversize Frame Counter
This is a 8-bit counter that counts the number of receive
frames with greater than the 1518 byte maximum frame
size of data. Upon reaching its maximum count value of FF
hex, this counter will stop counting. During reading of this
counter the count value will be frozen to prevent incrementing while being read. Should the 84C300A attempt to
increment the counter while it is frozen, then the counter
will be loaded with 01 hex upon completion of the read.
Otherwise, completing the read will reset the counter to 00
hex.
Alignment Error Counter
This is a 16 bit read only counter that counts the number
of frames received or discarded with a framing error and a
CRC error both. Upon reaching its maximum count value
of FFFF hex, this counter will stop counting. To read this
counter, two consecutive reads need to be performed to
the same address location. The first read, reads out the
4-35
35
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
ABSOLUTE MAXIMUM RATINGS
VCC Supply Voltage ...................................-.3V to 6.0V
Absolute maximum ratings are limits beyond which may
cause permanent damage to the device or affect device
reliability. All voltages are specified with respect to GND,
unless otherwise specified.
All Inputs and Outputs
with Respect to GND ........................-.3V to VCC+.3V
4.0 DC Characteristics
Package Power Dissipation ............... 2.2 Watt @ 70 °C
Storage Temperature ...............................-65 to +150°C
Temperature Under Bias............................. -10 to +80°C
Lead Temperature (Soldering, 10 Sec) .............. 260°C
Body Temperature (Soldering, 30 Sec) ...............220°C
TA = 0° C to 70°C, VCC = 5 V ± 5%
Limits[1]
Symbol
Parameter
IIN
Min.
Typ.
Max.
Units
Input Leakage Current
10
µA
VIN = 0.45 V to 5.25 V
IO
Output Leakage Current
10
µA
VOUT = 0.45 V to 5.25 V
ICC
VCC Current
300
mA
VCH
Clock Input High Voltage
VCL
Clock Input Low Voltage
0.8
V
VIL
Input Low Voltage
0.8
V
VIH 1
Input High Voltage
VOL
Output Low Voltage
RXTXDATA [31:0], RXTXEOF,
SPDTAVL, TXRDY_[1:4],
RXRDY_[1:4], TXRET_[1:4],
250
2.0
Condition
V
2.0
V
0.4
V
IOL = 8 mA
V
IOH = 8 mA
V
IOL = 4 mA
V
IOH = 4 mA
V
IOL = 2 mA
V
IOH = 2 mA
RXDC_[1:4]
VOH
Output High Voltage
RXTXDATA [31:0], RXTXEOF,
SPDTAVL, TXRDY_[1:4],
RXRDY_[1:4], TXRET_[1:4],
RXDC_[1:4]
VOL
Output Low Voltage
TXD [0:3]_[1:4],
TXEN_[1:4]
VOH
Output High Voltage
TXD [0:3]_[1:4],
TXEN_[1:4]
VOL
Output Low Voltage
All Other Outputs
VOH
Output High Voltage
All Other Outputs
2.4
0.4
2.4
0.4
2.4
NOTE:
1. Typical values are for T A = 25°C and nominal supply voltages.
36
4-36
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
AC Test Conditions
Capacitance
Output Load: 1 Schottky TTL Gate + CL = 100 pF
except where specifically given otherwise in the condition
column.
Input Pulse Level:0.4 V to 2.4 V
Timing Reference Level:1.5 V
TA = 25°C, FC = 1 MHz
Symbol Parameter
Maximum
Condition
CIN
Input Capacitance
15 pF
VIN = 0 V
CI/O
I/O Capacitance
15 pF
VI/O = 0 V
5.0 COMMAND/STATUS INTERFACE TIMING
AC Characteristics
TA = 0° C to 70° C, VCC = 5 V ± 5%
Limits
[1]
Symbol
Parameter
TDBD
Receive/Transmit
Command Status, and
Management Counters
Delay
Min.
Typ.
0.5 RXC/TXC
Cycles + 10 ns
Units
Max.
(ns)
1.5 RXC/TXC
Cycles + 50 ns
ns
All Other Registers
10
50
ns
TDBR
CDST [7:0]
Bus Release Delay
1.5
5.5
ns
TDBS
CDST [7:0]
Bus Siezure Delay
6
32
ns
THA
A[3:0] Hold
10
ns
THCS
CDST Bus Hold
0
ns
THPS
REGPS[1:0] Hold
10
ns
THEN
ENREGIO Hold
10
ns
TSA
A[3:0] Setup
15
ns
TSCS
CDST Bus Setup
10
ns
TSPS
REGPS[1:0] Setup
15
ns
TSEN
ENREGIO Setup
15
ns
TRWH
RD/ High Width
1 TXC/RXC
Cycle
ns
TRWL
RD/ Low Width
1.5 TXC/RXC
Cycles + 70 ns
ns
TWWH
WR High Width
30
ns
TWWL
WR Low Width
30
ns
4-37
37
MD400152/E
Condition
84C300A 4-Port
Fast Ethernet Controller
5.01 Command/Status Interface Read Timing
TRWL
RD
TRWH
TSEN
THEN
ENREGIO
THPS
TSPS
REGPS[1:0]
THA
TSA
A0-A3
TDBS
TDBR
CDST[7:0]
TDBD
DATA VALID
5.02 Command/Status Interface Write Timing
TW
WR
TWWH
TSEN
ENREGIO
THPS
TSPS
REGPS[1:0]
TSA
A0-A3
THA
TSCS
CDST[7:0]
THCS
38
4-38
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
6.0 Ethernet Transmit and Receive Interface Timing
AC Characteristics
TA = 0° C to 70° C, VCC = 5 V ± 5%
ETHERNET TRANSMIT INTERFACE TIMING
Limits
Symbol
Parameter
Min.
Typ.
TDTD
TXD/TXEN Delay
5 ns
TWHTC
TXC High Width
1 TXC Cycle/2 – 5
TWLTC
TXC Low Width
1 TXC Cycle/2 – 5
Max.
Condition
20 ns
ETHERNET RECEIVE INTERFACE TIMING
THRD
RxD Hold
5 ns
TSRD
RxD Setup
5 ns
TWHRC
RxC High Width
1 RXC Cycle/2 – 5
TWLRC
RxC Low Width
1 RXC Cycle/2 – 5
6.01 Ethernet Transmit Interface Timing
TWHTC
TWHTC
TWLTC
TxC
10 MBIT SERIAL MODE
TxC
TDTD
MII MODE
TDTD
TxD
TxD
TDTD
TDTD
TxEN
TxEN
TDTD
TDTD
6.02 Ethernet Receive Interface Timing
TWHRC
TWLRC
RxC
TSRD
RxD
THRD
CSN
4-39
39
MD400152/E
TWLTC
TPCK
TPCK
84C300A 4-Port
Fast Ethernet Controller
7.0 Transmit Data Interface Write Timing
Symbol
Parameter
Min.
t1
Transmit Interface Enable
to Clock Setup Time
5 ns
t2
Transmit Write Enable
to Clock Setup Time
5 ns
t3
Transmit Interface Enable
to Transmit Write Enable
Timing Skew
0 ns
t4
Port Select Inputs
to Clock Setup Time
5 ns
t5
TXRDY Output Enabled
to Output Valid Delay
5 ns
25 ns
t6
SPDTAVL Output Enable
to Output Valid Delay
4 ns
24 ns
t7
Transmit Data, Byte
Enables, TXEOF, TXNOCRC
to Clock Setup Time
5 ns
t8
Transmit Data, Byte
Enables, TXEOF, TXNOCRC
Hold Time
0 ns
t9
TXRDY Deassert Due to
Threshold Being Met
5 ns
25 ns
t10
SPDTAVL Output Disabled
to Hi-Z Delay
3 ns
14 ns
t11
TXRDY Output Disabled
to Hi-Z Delay
3 ns
13 ns
t12
Port Select Inputs
Hold Time
0 ns
t13
Transmit Write Enable
Hold Time
0 ns
t14
Transmit Interface
Enable Hold Time
0 ns
t15
SPDTAVL Deassert Due to
Transmit FIFO Reading, an almost
Empty Condition
4 ns
40
4-40
MD400152/E
Typ.
Max.
24 ns
84C300A 4-Port
Fast Ethernet Controller
7.01 Transmit Data Interface Write Timing 1
1
2
3
4
5
6
7
9
RXRD_TXWR
t1
t3
TXINTEN
t9
t5
TXRDY
t4
t 12
RXTXPS[1:0]
t2
t 13
TXWREN
t7
RXTXDATA[31:0]
1
t8
2
3
4
5
6
t7
7
8
t8
RXTXBE[3:0]
t 15 [1]
t6
SPDTAVL
t8
t7
TXNOCRC
Notes: 1. SPDTAVL gets deasserted because of the 7th double word write to the transmit FIFO indicating that the 8th
double word write will fill the FIFO completely. It is important to note that the data gets pipelined internally, hence
the 7th external double word write (The 7th Clock Edge that latches in the active low TXWREN) actually happens
on the 8th clock cycle internally.
4-41
41
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
7.02 Transmit Data Interface Write Timing 2
n-3
n-2
n-1
n
RXRD_TXWR
t14
TXINTEN
t2
TXWREN
RXTXBE[3:0]
RXTXDATA[31:0]
n-3
n-2
n-1
n
t9
t 11
TXRDY
t 10
SPDTAVL
t7
RXTXEOF
t8
t7
TXNOCRC
42
4-42
MD400152/E
t8
84C300A 4-Port
Fast Ethernet Controller
8.0 Receive Data Interface Read Timing
Symbol
Parameter
Min.
t1
Receive Interface Enable
to Clock Setup Time
5ns
t2
Receive Read Enable
to Clock Setup Time
5 ns
t3
Receive Interface Enable
to Receive Read Enable
Timing Skew
0 ns
t4
SPDTAVL Output Enabled to
Output Valid Delay
4 ns
t5
Receive Byte Enables
to Clock Setup Time
5 ns
t6
Port Select Inputs
to Clock Setup Time
5 ns
t7
RXRDY Output Enabled
to Output Valid Delay
4 ns
26 ns
t8
RXTXDATA [31:0], RXTXEOF
Outputs Enabled to Outputs
Valid Delay
5 ns
22 ns
t9
FIFO Read Strobe High to
RXTXEOF, RXTXDATA[31:0]
FIFO Data Out Delay
5 ns
24 ns
t10
Clock to SPDTAVL Low Delay
SPDTAVL Deassert to Assert
Minimum Low Time
Typ.
Max.
Condition
24 ns
22 ns
8 RXRD_TXWR
Cycles
If Both RXDEN and RXINTEN
are Asserted
t12
SPDTAVL Output Disabled
to Hi-Z Delay
3 ns
14 ns
t13
RXRDY Output Disabled to
Hi-Z Delay
3 ns
12 ns
t14
Receive Data and RXTXEOF
Outputs Disabled to Hi-Z Delay
3 ns
13 ns
t15
RXRD_TXWR Clock Pulse
Width High
12 ns
t16
RXRD_TXWR Clock Pulse
Width Low
12 ns
t17
RXRD_TXWR Clock Period
30 ns
125 ns
TXC/RXC = 10 MHz
30 ns
50 ns
TXC/RXC = 25 MHz
30 ns
500 ns
TXC/RXC = 2.5 MHz
t18
Port Select Inputs
Hold Time
0 ns
t19
Byte Enables Hold Time
0 ns
t20
Receive Read Enable
Hold Time
0 ns
t21
Receive Interface Enable
Hold Time
0 ns
4-43
43
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
Receive Data Interface Timing (cont’d)
Symbol
Parameter
Min.
Typ.
Max.
t22
RXRDY Deassert Due to Emptying
RX FIFO Below Threshold
4 ns
26 ns
t23
RXRDY Assert from CSN Going
Low Due to Status Write
9 RXC Cycles
+ 2.5 RXRD_TXWR
Cycles + 4 ns
(10
MBit/sec
Serial
Mode)
17 RXC Cycles
+ 3.5 RXRD_TXWR
Cycles + 22 ns
(10
MBit/sec
Serial
Mode)
3 RXC Cycles
+ 2.5 RXRD_TXWR
Cycles + 4 ns
(MII Mode)
5 RXC Cycles
+3.5 RXRD_TXWR
Cycles + 22 ns
(MII Mode)
Condition
8.01 Receive Data Interface Read Timing 1
t 15
1
2
3
4
5
6
7
8
RXRD_TXWR
t 17
t 16
t1
t3
RXINTEN
t7
t 23
RXRDY
t6
RXTXPS[1:0]
t2
RXRDEN
t9
t8
1
RXTXDATA[31:0]
2
3
4
5
6
7
t5
RXTXBE[3:0]
1
2
3
4
5
6
7
t19
t4
SPDTAVL
t8
RXTXEOF
Notes: 1. SPDTAVL gets deasserted because of the 7th double word read from the receive FIFO indicating that there is
no more data available in the receive FIFO and further reads will cause invalid reads. Here, it is important to note
that the 7th read is referred to the 7th clock edge that latches in the active low RXRDEN and the resultant data
can be latched out on the 8th clock edge because of the pipelining effect.
44
4-44
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
8.02 Receive Data Interface Read Timing 2
n-3
n-2
n-1
Stat
n
RXRD_TXWR
t 21
RXINTEN
t 13
t 22
RXRDY
t7
t 18
RXTXPS[1:0]
RXRDEN
t 14
t8
RXTXDATA[31:0]
n-3
n-2
n-1
n
Stat
RXTXBE[3:0]
t8
RXTXEOF
CSN
t 23
t 12
t4
SPDTAVL
4-45
45
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
9.0 Transmit Data Interface Timing on Exception Conditions
Symbol
Parameter
Min.
t1
TXINTEN Setup Time
5 ns
t2
RXRD_TXWR to TXRET Delay
t3
TXRET Deassert from CLRTXERR
t4
TXWREN Setup Time
5 ns
t5
TXWREN Hold Time
0 ns
t6
CLRTXERR Setup Time
12 ns
t7
CLRTXERR Hold Time
0 ns
t8
TXRDY Output Enabled to Output
Valid Delay
5 ns
25 ns
t9
TXRDY Deassert Due to TXRET
Going HIGH Because of
an Exception Condition
5 ns
1 RXRD_TXWR Cycle
+ 25 ns
t10
RXTXDATA Setup Time
t12
TXEN Assert from First Data
Write to the Transmit FIFO
(Assuming Defer Time Has Been
Met)
t13
TXRET Set Delay Due to
Late Collision or 16 Collisions
TXRET Set Due to Underflow
Typ.
Max.
7 ns
25 ns
1 TXC Cycle
+ 1 RXRD_TXWR Cycle
+ 7 ns
2 TXC Cycles
+ 2 RXRD_TXWR Cycles
+ 30 ns
5 ns
0.75 RXRD_TXWR Cycles
+ 18.5 TXC Cycles + 5 ns
(10 Mbit/sec Serial Mode)
0.75 RXRD_TXWR Cycles
+ 26.5 TXC Cycles + 20 ns
(10 Mbit/sec Serial Mode)
0.75 RXRD_TXWR Cycles
+ 6.5 TXC Cycles + 5 ns
(MII Mode)
0.75 RXRD_TXWR Cycles
+ 8.5 TXC Cycles + 20 ns
(MII Mode)
25 TXC Cycles
+ 1 RXRD_TXWR Cycle
+ 7 ns
(10 Mbit/sec Serial Mode)
34 TXC Cycles
+2 RXRD_TXWR Cycles
+ 25 ns
(10Mbit/sec Serial Mode)
7 TXC Cycles
+ 1 RXRD_TXWR Cycle
+ 7 ns
(MII Mode)
10 TXC Cycles
+ 2 RXRD_TXWR Cycles
+ 25 ns
(MII Mode)
8 TXC Cycles
+ 1 RXRD_TXWR Cycle
+ 7 ns
(10 Mbit/sec Serial Mode)
8 TXC Cycles
+ 2 RXRD_TXWR Cycles
+ 25 ns
(10 Mbit/sec Serial Mode)
2 TXC Cycles
+ 1 RXRD_TXWR Cycle
+ 7 ns
(MII Mode)
2 TXC Cycles
+ 2 RXRD_TXWR Cycles
+ 25 ns
(MII Mode)
t15
TXRDY Going HIGH Due to TXRET
Going Low
5 ns
25 ns
t16
TXRET Output Enabled
to Output Valid Delay
7 ns
25 ns
t17
TXRET Output Disabled to Hi-Z
Delay
3 ns
12 ns
46
4-46
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
9.0 Transmit Data Interface Timing on Exception Conditions (continued)
Symbol
Parameter
t18
t19
Min.
1 TXC Cycle
– 3 ns
1 TXC Cycle
+ 3 ns
TXEN Low to INT HIGH Delay
Due to Carrier Sense Dropout
1 TXC Cycle
– 3 ns
1 TXC Cycle
+ 3 ns
TXEN Low to INT High
Delay Due to Successful
Transmission
1 TXC Cycle
– 3 ns
1 TXC Cycle
+ 3 ns
20 TXC Cycles + 3 ns
(10 Mbit/sec Serial Mode)
27 TXC Cycles + 15 ns
(10 MBit/sec Serial Mode)
8 TXC Cycles + 3 ns
(MII Mode)
9 TXC Cycles + 15 ns
(MII Mode)
1.5 TXC Cycles
+ 6 ns
2.5 TXC Cylces
+ 30 ns
INT Clear Delay
9.01 Transmit Data Interface Timing on Exception Conditions
RXRD_TXWR
t1
TXINTEN
t8
t9
TXRDY
t3
t2
t 16
TXRET
t4
TXWREN
t5
t 10
RXTXDATA[31:0]
SPDTAVL
t 12
TXEN
t 13
LATE
COLL
t6
4-47
47
MD400152/E
Max.
INT High to TXEN Low Delay
Due to Underflow
COLL High to INT High Delay
t20
Typ.
84C300A 4-Port
Fast Ethernet Controller
10.0 Receive Data Interface Timing on Exception Conditions
Symbol
t1
Parameter
Min.
Typ.
Max.
Receive INT Delay Due to
Shortframe, CRC, Good Frame,
or Oversized Packet
2 RXC Cycles
+ 3 ns
2 RXC Cycles
+ 15 ns
Receive INT Delay Due to
Overflowed Packet
2 RXC Cycles
+ 3 ns
18 RXC Cycles
+ 15 ns
1.5 RXC Cycles
+ 6 ns
2.5 RXC Cycles
+ 30 ns
t2
INT Clear Delay
t3
CLRRXERR Setup Time
to RXRD_TXWR
6 ns
t4
CLRRXERR to
RXRD_TXWR Hold Time
0 ns
t5
CLRRXERR High to
RXDC Low Delay
t6
1 RXC Cycle
+ 3 RXRD_TXWR
Cycles + 6 ns
2 RXC Cycles
+ 4 RXRD_TXWR
Cycles + 30 ns
RXRDY Deassert Due to
Discard to RXDC High Delay
5 ns
1 RXRD_TXWR
Cycle + 11 ns
t7
RXRD_TXWR to RXDC
Delay
7 ns
25 ns
t8
SPDTAVL Deassert Due to
Discard to RXDC High Delay
5 ns
1 RXRD_TXWR
Cycle + 13 ns
t9
RXRD_TXWR to RXDC Hi-Z
3 ns
11 ns
t10
CSN Deassert to RXDC High
Due to Receive Overflow
Condition
2 RXC Cycles
+ 3 RXRD_TXWR
Cycles + 7 ns
(10
MBit/sec
Serial
Mode)
18 RXC Cycles
+ 4 RXRD_TXWR
Cycles + 25 ns
(10
MBit/sec
Serial
Mode)
2 RXC Cycles
+ 3 RXRD_TXWR
Cycles + 7 ns
(MII Mode)
6 RXC Cycles
+ 4 RXRD_TXWR
Cycles + 25 ns
(MII Mode)
2 RXC Cycles
+ 3 RXRD_TXWR
Cycles + 7 ns
2 RXC Cycles
+ 4 RXRD_TXWR
Cycles + 25 ns
t10a*
t11
RXDC High From Point of
Detection of Receive Packet
with Greater than 1518 Bytes
RXABORT Pulse Width
1.5 RXC
RXABORT is
Asynchronously
Asserted with
Respect to RXC
RXABORT to RXC
Setup Time
5 ns
RXABORT is
Synchronously
Asserted with
Respect to RXC
RXC to RXABORT
Hold Time
5 ns
* Not shown on the timing diagram.
48
4-48
MD400152/E
Condition
84C300A 4-Port
Fast Ethernet Controller
10.01 Receive Data Timing Diagram on Exception Conditions
RXRD_TXWR
RXINTEN
t6
RXRDY
t7
t9
RXDC
t 10
RXRDEN
Invalid Invalid Invalid Invalid
RXTXDATA[31:0]
t8
SPDTAVL
t 11
RXABORT
t4
t3
CLRRXERR
t1
INT
t2
RD_B
4-49
49
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
11.0 Reset Timing
Symbol
Parameter
Min.
t1
Asynchronous
Reset Pulse Width
10 µs
t2
Reset Completion to
Normal Operation Delay
Typ.
10 RXDR_TXWR
Cycles
1
2
TXC
RXC
t1
RESET
RXRDEN
TXWREN
50
4-50
MD400152/E
Condition
All clocks must be active
during this peroid of time
11.0 Reset Timing
RXRD_TXWR
Max.
3
84C300A 4-Port
Fast Ethernet Controller
Ordering Information
Q
Q
84C300A
PACKAGE
TYPE
TEMPERATURE
RANGE
PART TYPE
PLASTIC QUAD FLATPACK
208 Pin PQFP
Q – 0°C to +70°C
EDLC
SEEQ Hurricane, Full Duplex Designation
Full Duplex
SEEQ’s Hurricane family of products
offer 100MBit Fast Ethernet Solutions. Symbol indentifies product as
a part of SEEQ’s Hurricane family.
Symbol indentifies product as
Full Duplex device.
TM
HURRICANE
Revision History
4/19/96
Page 21- Using the 84C300A in 8 Bit or 16 Bit Mode sub section has been added to Section 3.5.2.
Page 21- Section 3.5.3: The end of the second paragraph in this section has been replaced with the new sub section
Using the 84C300A in 8 Bit or 16 Bit Mode.
Page 27- Receive Own Transmit Disable Mode has been deleted and replaced with new sub section Disable Loopback
Mode and new table Configuration Register #1.
Page 27- Section 3.6.9 has been entirely replaced with new copy.
11/4/96
Page 4, Pin Description:
- Pin 35 Description now reads; This is the system clock acting as the chip’s ...
- Pin 39 Description now reads; This is an active high output that can be used for validating reads from the receive
FIFO during a read operation and preventing over writes to the transmit FIFO
during a write operation. For further details, please refer to the Transmit Data
Write timing and the Receive Data Read timing diagrams.
Page 13 - Section 2.0 Introduction has been deleted and replaced with new Section 2.0 Introduction.
Page 19 - Section 3.3.5 Second paragraph, now reads; Except for discards due to address mismatches and
oversized packets, all packet ...
Page 25 - Format of the Status Double Word, illustration has been added.
Page 27 - Configuration Register #1 Illustration has been changed; now reads, Bit 5 = ‘1’ Enables Full Duplex Mode
[Bit 3 should be ‘0’].
4-51
51
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
Revision History
Page 30 - In Sections: CRC Error Counter, Runt Frame Counter, Alignment Error Counter, Transmit Collision Counter
Receive Collision Counter; copy has changed ... To read this counter, two consecutive reads need to be
performed to the same address location. The first read, reads out the high byte followed by the second, that will
read out the low byte. Upon reading ...
Page 31, DC Characteristics:
- Clock Input High Voltage (Limits Min.), has been changed from 3.5 to 4.0.
Page 32, AC Characteristics:
- TDBD (min) has been changed from 100 to 0.5 RXC/TXC Cycles + 10 ns.
- TDBD (max) has been changed from 200 to 1.5 RXC/TXC Cycles + 50 ns.
- TDBD, All Other Registers (min) is now 10.
- TDBR (min) has been changed from 7 to 1.5.
- TDBR (max) has been changed from 20 to 5.5.
- TDBS (min) has been changed from 10 to 6.
- TDBS (max) has been changed from 20 to 32.
- Symbol THAR has been changed to THA.
- THA Parameter has been changed from A0-2/Reg PS[1:0] Hold to A[3:0] Hold.
- Symbol TSAR has been changed to TSA.
- TSA Parameter has been changed from A0-2/Setup to A[3:0] Setup.
- THCS row is new.
- Symbol TWCH has been changed to TRWH.
- TRWH Parameter has been changed from RD/WR High Width, to RD High Width.
- TRWH (min) has been changed from 200 to 1 TXC/RXC Cycle.
- Symbol TWCL has been changed to TRWL.
- TRWL Parameter has been changed from RD/WR Low Width to RD Low Width.
- TRWL (min) has been changed from 200 to 1.5 TXC/RXC Cycles + 70 ns.
- TWWH row is new.
- TWWL row is new.
Pages 33 to 40, has been deleted and replaced with new Tables and Timing Diagrams, also the pagination has changed.
- Page 33, New Timing Diagrams, 5.01 Command/Status Interface Read Timing, and 5.02 Command/Status
Interface Write Timing.
- Page 34, New Timing Diagrams, 6.01 Ethernet Transmit Interface Timing, and 6.02 Ethernet Receive Interface
Timing.
- Page 34, New Table 6.0 Ethernet Transmit and Receive Interface Timing.
- Page 35, New Table, 7.0 Transmit Data Interface Timing.
- Page 36, New Timing Diagram, 7.01 Transmit Data Interface Write Timing 1.
- Page 37, New Timing Diagram, 7.02 Transmit Data Interface Write Timing 2.
- Page 38, New Table, 8.0 Receive Data Interface Timing.
- Page 39, New Timing Diagram, 8.01 Receive Data Interface Read Timing 1.
- Page 40, New Timing Diagram, 8.02 Receive Data Interface Read Timing 2.
- Page 41, New Table, 9.0 Transmit Data Interface Timing on Exception Conditions.
- Page 42, New Timing Diagram, 9.0 Transmit Data Timing on Exception Conditions.
- Page 43, New Table, 10.0 Receive Data Interface Timing on Exception Conditions.
- Page 44, New Timing Diagram, 10.0 Receive Data Timing on Exception Conditions.
12/4/96
Page 18; Internal Port Register Addressing Table
- Register Description Read, Dribble Error Counter has been changed to Alignment Error Counter.
Page 47; 208 Pin PQFP Dimension Diagram, illustration has changed.
52
4-52
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
Revision History
2/6/97
2/6/97 - Document revision changed to MD400152/D.
Page 2, 5.0 AC Characteristics has been changed to 5.0 Command/Status Interface Timing.
Page 14, Section, 3.2.2 Transmission Initiation/Deferral has been changed to 3.2.2 Transmission Initiation in Full Duplex
and CSMA/CD Networks, and this section has been replaced with new copy.
Page 18, Pagination changed has occurred from pages 18 to 22.
Page 18, Conditions that Cause the RXDC Pin to go HIGH
- First sentence copy change ...in the section “Description of How Receive Packets are Discarded”... has been
changed to ...in the section “Receive Discard Conditions”.
Page 19, 3.5.1 Little Endian and Big Endian Format.
- First sentence copy change...BUSMODE bit 6 in configuration... has been changed to ...BUSMODE bit 7 in
configuration...
Page 20, 3.5.2 Transmit FIFO Interface.
- Paragraph 4 last sentence copy change ...one more write after... has been changed to ...one more internal
FIFO write after...
Page 21. 3.6 Register Interface
- Paragraph 1, first sentence copy change ...and A[2:0] signals... has been changed to ...and A[3:0] signals...
Page 26, Section Receive Without Discard Mode, Bit 4 has been added.
Page 27, Section Disable Loopback Mode, new text has been added.
Page 27, Configuration Register #1
- Bit 3, 0 (Default), Bit 5, 0 (Default) Loopback Mode, and Function Description, have been added.
- Note has been added to Configuration Register #1.
Page 27, Half Duplex Mode Section has been deleted.
Page 27, Full Duplex Mode Section has been deleted.
Page 28, Full Duplex Mode
- ...Please refer to the previous table for more details... has been added.
Page 31, 4.0 DC Characteristics
- VCH (Min) has changed from 4.0 to 2.0.
- VCH (Max) has changed from 6 to Vcc +0.5.
- VCL (Min) is now –0.5.
- VIL (Min.) is now –0.5.
- VIH1 (Max) has changed from 6 to Vcc +0.5
Page 38, 8.0 Receive Data Interface Timing
- t17 (Max) has changed from 180 ns to 125 ns.
Page 41, 9.0 Transmit Data Interface Timing on Exception Conditions
- t2 (Min) has changed from 9.5 ns to 7 ns.
- t2 (Max) has changed from 38 ns to 25 ns.
- t3 (Max) has changed from 28 ns to 30 ns.
- t13 (Min) all references to 9.5 ns have changed to 7 ns.
- t13 (Max) all references to 38 ns have been changed to 25 ns.
- t16 (Min) has changed from 9.5 ns to 7 ns.
- t16 (Max) has changed from 38 ns to 25 ns.
4-53
53
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
Revision History
Page 42, 9.0 Transmit Data Interface Timing on Exception Conditions
- t18 INT HIGH (Min) reference to 15 ns has been changed to 3ns.
- t18 INT HIGH (Max) reference to 40 ns has been changed to 15 ns.
- t18 TXEN Low Sense Dropout (Min) is now 3 TXC Cycle +3 ns.
- t18 TXEN Low Sense Dropout (Max) is now 3 TXC Cycle +15 ns.
- t18 TXEN Low Successful Transmission (Min) is now 1 TXC Cycle +3 ns.
- t18 TXEN Low Successful Transmission (Max) is now 1 TXC Cycle +15 ns.
- t19 (Min) reference to 15 ns has changed to 3 ns.
- t19 (Max) reference to 40 ns has been changed to 15 ns.
- t20 (Min) reference to 15 ns has changed to 6 ns.
- t20 (Max) reference to 40 ns has changed to 30 ns.
Page 43, 10.0 Receive Data Interface Timing on Exception Conditions
- t1 (Min) all references to 15 ns have been changed to 3 ns.
- t1 (Max) all references to 40 ns have been changed to 15 ns.
- t2 (Min) has been changed from 15 ns to 6 ns.
- t2 (Max) has been changed form 40 ns to 30 ns.
- t5 (Max) has been changed from 27 ns to 30 ns.
- t7 (Min) has been changed from 9 ns to 7 ns.
- t7 (Max) has been changed from 37 ns to 25 ns.
- t10 (Min) all references to 9 ns have been changed to 7 ns.
- t10 (Max) all references to 37 ns have been changed to 25 ns
- t10a (Min) references to 9 ns have been changed to 7 ns.
- t10a (Max) references to 37 ns have been changed to 25 ns.
3/12/97
- Major edits to Data Sheet
4/2/97
- All references to RXRD_TXWR have been changed to RXRD_TXWR.
Page 37: 5.0 Command/Status Interface Timing, AC Characteristics
- THDA row has been deleted.
- TDBD, TRWH, TRWL, Conditions have been deleted.
- Rows THEN, TSEN, THPS, TSPS have been added.
Page 40: 7.0 Transmit Data Interface Write Timing
- Symbol t8 (min) has been changed from 1.5 ns to 0 ns.
Page 41: 7.01 Transmit Data Interface Write Timing 1
- Timing TXNOCRC, has been changed.
Page 42: 7.02 Transmit Data Interface Write Timing 2
- Timing TXNOCRC, has been changed.
Page 47: 9.0 Transmit Data Interface Timing on Exception Conditions (continued)
- t18, Int High to TXEN Low (min) has been changed from 1 TXC Cycle +3 ns to 1 TXC Cycle - 3 ns.
- t18, Int High to TXEN Low (max) has been changed from 1 TXC Cycle +15 ns to 1 TXC Cycle + 3 ns.
- t18, TXEN Low to INT HIGH Carrier Sense Dropout (min) has been changed from 3 TXC Cycles + 3 ns
to 1 TXC Cycle - 3 ns.
- t18, TXEN Low to INT HIGH Carrier Sense Dropout (max) has been changed from 3 TXC Cycles + 15 ns
to 1 TXC Cycle + 3 ns.
- t18, TXEN Low to INT High Successful Transmission (min) has been changed from 1 TXC Cycle + 3 ns
to 1 TXC Cycle - 3 ns.
- t18, TXEN Low to INT High Successful Transmission (max) has been changed from 1 TXC Cycle + 15 ns
to 1 TXC Cycle + 3 ns.
54
4-54
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
Revision History
3/19/98
Document Revision change to MD400152/E
Page 2 - Table of Contents Reference to 11.0 Reset Timing added.
Page 50 - 11.0 Reset Timing Table and Timing Diagram added.
4-55
55
MD400152/E
84C300A 4-Port
Fast Ethernet Controller
208 Pin PQFP
30.60 ± 0.30
28.00 ± 0.20
30.60 ± 0.30
28.00 ± 0.20
0.15 ±0.10 –0.05
QQ84C300A
0.10 MAX
See Detail A
#208
#1
0.25 min.
1.25
3.40 ± 0.20
0.20 ± 0.10
0.50
4.10 Max.
0 - 8°
Detail A
1. All dimensions are in (millimeters).
56
4-56
MD400152/E
0.50 ± 0.20