Datasheet

Rev. B | Page 16 of 68 | March 2013
ADSP-21483/ADSP-21486/ADSP-21487/ADSP-21488/ADSP-21489
MLBCLK
1
I Media Local Bus Clock. This clock is generated by the MLB controller that is synchro-
nized to the MOST network and provides the timing for the entire MLB interface at
49.152 MHz at FS=48 kHz. When the MLB controller is not used, this pin should be
grounded.
MLBDAT
1
I/O/T in 3
pin mode. I
in 5 pin
mode.
High-Z Media Local Bus Data. The MLBDAT line is driven by the transmitting MLB device and
is received by all other MLB devices including the MLB controller. The MLBDAT line
carries the actual data. In 5-pin MLB mode, this pin is an input only. When the MLB
controller is not used, this pin should be grounded.
MLBSIG
1
I/O/T in 3
pin mode. I
in 5 pin
mode
High-Z Media Local Bus Signal. This is a multiplexed signal which carries the Channel/Address
generated by the MLB Controller, as well as the Command and RxStatus bytes from
MLB devices. In 5-pin mode, this pin is input only. When the MLB controller is not used,
this pin should be grounded.
MLBDO
1
O/T High-Z Media Local Bus Data Output (in 5 pin mode). This pin is used only in 5-pin MLB mode.
This serves as the output data pin in 5-pin mode. When the MLB controller is not used,
this pin should be connected to ground.
MLBSO
1
O/T High-Z Media Local Bus Signal Output (in 5 pin mode). This pin is used only in 5-pin MLB
mode. This serves as the output signal pin in 5-pin mode. When the MLB controller is
not used, this pin should be connected to ground.
TDI I (ipu) Test Data Input (JTAG). Provides serial data for the boundary scan logic.
TDO O/T High-Z Test Data Output (JTAG). Serial scan output of the boundary scan path.
TMS I (ipu) Test Mode Select (JTAG). Used to control the test state machine.
TCK I Test Clock (JTAG). Provides a clock for JTAG boundary scan. TCK must be asserted
(pulsed low) after power-up or held low for proper operation of the device.
TRST
I (ipu) Test Reset (JTAG). Resets the test state machine. TRST must be asserted (pulsed low)
after power-up or held low for proper operation of the processor.
EMU
O (O/D, ipu) High-Z Emulation Status. Must be connected to the ADSP-2148x Analog Devices DSP Tools
product line of JTAG emulators target board connector only.
Table 11. Pin Descriptions (Continued)
Name Type
State
During/
After Reset Description
The following symbols appear in the Type column of this table: A = asynchronous, I = input, O = output, S = synchronous, A/D = active drive,
O/D = open drain, and T = three-state, ipd = internal pull-down resistor, ipu = internal pull-up resistor.
The internal pull-up (ipu) and internal pull-down (ipd) resistors are designed to hold the internal path from the pins at the expected logic
levels. To pull-up or pull-down the external pads to the expected logic levels, use external resistors. Internal pull-up/pull-down resistors cannot
be enabled/disabled and the value of these resistors cannot be programmed. The range of an ipu resistor can be between 26 kΩ–63 kΩ. The
range of an ipd resistor can be between 31 kΩ–85kΩ. The three-state voltage of ipu pads will not reach to the full V
DD_EXT
level; at typical
conditions the voltage is in the range of 2.3 V to 2.7 V.
In this table, all pins are LVTTL compliant with the exception of the thermal diode pins.