MU9C8338 10/100Mb Ethernet Filter Interface
Pin Descriptions
/FI (LANCAM Bus Full Flag, Input, TTL)
LANCAM Interface
The /FI LANCAM Full flag input is used to indicate to the
MU9C8338 the condition of the LANCAM Full flag. The
/FF output from the LANCAM should be connected to this
pin. If more than one LANCAM is used, /FI should be
connected to the /FF of the last device in the daisy chain.
See Timing Diagrams: Timing Data for LANCAM
Interface.
DQ[15:0] (LANCAM Bus, Input/Output, Tri-state, TTL)
DQ[15: 0] tri-state 16- bit bus transfers data or instructions
between the MU9C8338 and the LANCAM. When no
data or instructions are present on the bus, the bus goes
HIGH-Z.
/RESET_LC (Reset LANCAM, Output, TTL)
/RESET_LC is LOW whenever /RESET is LOW. It is
taken HIGH only by writing to bit 0 in the System
Dynamic Configuration (SDCFG) register. See SDCFG
register information.
/E (LANCAM Bus Enable, Output, Tri-state, TTL)
The /E chip enable is taken LOW to initiate LANCAM
activity. On LANCAM read cycles, /E is taken HIGH after
the MU9C8338 registers the data.
Test
SC_ENB (Scan Enable)
/W (LANCAM Bus Write, Output, Tri-state, TTL)
Enables scan chain for testing. Pin may be left
unconnected or tied to GND for normal operation
The MU9C8338 outputs /W (read/write select) to control
the direction of data flow between the MU9C8338 and the
LANCAM. If /W is LOW at the falling edge of /E, the
MU9C8338 outputs data on the DQ[15:0] bus for the
LANCAM as input. When /W is HIGH at the falling edge
of /E, the LANCAM outputs data on the DQ[15:0] bus to
the MU9C8338 as input.
TST_HLD, TST_HLD2 (Test Hold)
Enables test mechanism. Pins may be left unconnected or
tied to GND for normal operation.
JTAG
Note: Please refer to IEEE Standard 1149.1 for information on
using the mandatory JTAG functions. The optional HIGH-Z
function is implemented and may be activated by writing 0011 to
the JTAG Instruction register.
/CM (LANCAM Bus Command Mode, Output, Tri-state,
TTL)
The MU9C8338 outputs /CM Data/Command Select to
control whether the LANCAM interprets the DQ[15:0]
bus contents as command information or data. If both /CM
and /W are LOW at the falling edge of /E, the MU9C8338
outputs an instruction for the LANCAM to execute or a
value for one of the LANCAM configuration registers. If
/CM is LOW while /W is HIGH, then the LANCAM will
output data from one of its configuration registers to the
MU9C8338. If /CM is HIGH while /W is LOW, the
MU9C8338 will output data for the LANCAM to place in
one of its data registers or memory. If /CM is HIGH while
/W is HIGH, the LANCAM outputs data from one of its
data registers or memory to the MU9C8338.
/TRST (JTAG Reset, Input)
The /TRST is the Test Reset pin. It is internally pulled up
with a 3k minimum resistor. It must be tied to /RESET or
tied LOW when the JTAG port is not used.
TMS (JTAG Test Mode Select, Input)
The TMS input is the Test Mode Select input. This pin is
internally pulled up with a 3k minimum resistor.
TCK (JTAG Test Clock, Input)
The TCK input is the Test Clock input. It can be tied at a
valid logic level 1 when not in use. This pin is internally
pulled up with a 3k minimum resistor.
/EC (LANCAM Bus Enable Chain, Output, Tri-state,
TTL)
TDI (JTAG Test Data Input, Input)
The Daisy Chain Enable signal performs two functions.
The /EC signal enables the LANCAMs /MF output to
show the results of a comparison. If /EC is LOW at the
falling edge of /E in a cycle, the /MF flag output is
enabled; otherwise, /MF is held HIGH. The /EC signal
also enables the /MF-/MI daisy chain that serves to select
the device with the highest-priority match in a string of
LANCAMs.
The TDI input is the Test Data input. This pin is internally
pulled up with a 3k minimum resistor.
TDO (JTAG Test Data Output, Output)
The TDO output is the Test Data output.
Power and Ground
VDD, GND (Positive Power Supply, Ground)
These pins are the power supply connections to the
MU9C8338. VDD must meet the voltage supply
requirements in the Operating Conditions section relative
to the GND pins, which are at 0 Volts (system reference
potential), for correct operation of the device.
/MI (LANCAM Bus Match Flag, Input, TTL)
The /MI LANCAM Match flag input is used to indicate to
the MU9C8338 the conditions of the LANCAM Match
flag. The /MF output from the LANCAM should be
connected to this pin. If more than one LANCAM is used,
/MI should be connected to the /MF pin of the last
LANCAM in the daisy chain.
6
Rev. 1a