
ADSP-21060C/ADSP-21060LC
–9–
REV. PrA
PRELIMINARY
output.
Multiprocessing ID
. Determines which multiprocessing bus request (
BR1
 – 
BR6
) is used by ADSP-
2106x. ID = 001 corresponds to 
BR1
, ID = 010 corresponds to 
BR2
, etc. ID = 000 in single-processor
systems. T hese lines are a system configuration selection which should be hardwired or only changed
at reset.
Rotating Priority Bus Arbitration Select
. When RPBA is high, rotating priority for multiprocessor
bus arbitration is selected. When RPBA is low, fixed priority is selected. T his signal is a system con-
figuration selection which must be set to the same value on every ADSP-2106x. If the value of RPBA is
changed during system operation, it must be changed in the same CLK IN cycle on every ADSP-2106x.
Core Priority Access
. Asserting its 
CPA
 pin allows the core processor of an ADSP-2106x bus slave
to interrupt background DMA transfers and gain access to the external bus. 
CPA
 is an open drain
output that is connected to all ADSP-2106xs in the system. T he 
CPA
 pin has an internal 5 k
 pull-up
resistor. If core access priority is not required in a system, the 
CPA
 pin should be left unconnected.
Data T ransmit
 (Serial Ports 0, 1). Each DT  pin has a 50 k
 internal pull-up resistor.
Data Receive
 (Serial Ports 0, 1). Each DR pin has a 50 k
 internal pull-up resistor.
T ransmit Clock
 (Serial Ports 0, 1). Each T CLK  pin has a 50 k
 internal pull-up resistor.
Receive Clock
 (Serial Ports 0, 1). Each RCLK  pin has a 50 k
 internal pull-up resistor.
TECHNICAL
should be pulled high; the processor’s own 
BR
x line must not be pulled high or low because it is an
Pin
T ype
Function
SBTS
I/S
Suspend Bus Three-State
. External devices can assert 
SBTS
 (low) to place the external bus address,
data, selects and strobes in a high impedance state for the following cycle.  If the ADSP-2106x
attempts to access external memory while 
SBTS
 is asserted, the processor will halt and the memory
access will not be completed until 
SBTS
 is deasserted. 
SBTS
 should only be used to recover from host
processor/ADSP-2106x deadlock, or used with a DRAM controller.
Interrupt Request Lines
. May be either edge-triggered or level-sensitive.
Flag Pins
. Each is configured via control bits as either an input or output. As an input, it can be
tested as a condition. As an output, it can be used to signal external peripherals.
T imer E xpired
. Asserted for four cycles when the timer is enabled and T COUNT  decrements to
zero.
Host Bus Request
. Must be asserted by a host processor to request control of the ADSP-2106x’s
external bus. When 
HBR
 is asserted in a multiprocessing system, the ADSP-2106x that is bus master
will relinquish the bus and assert 
HBG
. T o relinquish the bus, the ADSP-2106x places the address,
data, select and strobe lines in a high impedance state. 
HBR
 has priority over all ADSP-2106x bus
requests (
BR
6-1
) in a multiprocessing system.
control of the external bus. 
HBG
 is asserted (held low) by the ADSP-2106x until 
HBR
 is released. In a
multiprocessing system, 
HBG
 is output by the ADSP-2106x bus master and is monitored by all others.
Chip Select
. Asserted by host processor to select the ADSP-2106x.
Host Bus Acknowledge
. T he ADSP-2106x deasserts REDY (low) to add wait states to an asynchro-
nous access of its internal memory or IOP registers by a host. Open drain output (O/D) by default; can
be programmed in ADREDY bit of SYSCON register to be active drive (A/D). REDY will only be
output if the 
CS
 and 
HBR
 inputs are asserted.
DMA Request 1
 (DMA Channel 7).
DMA Request 2
 (DMA Channel 8).
DMA Grant 1
 (DMA Channel 7).
DMA Grant 2
 (DMA Channel 8).
Multiprocessing Bus Requests
. Used by multiprocessing ADSP-2106xs to arbitrate for bus master-
ship. An ADSP-2106x only drives its own 
BR
x line (corresponding to the value of its ID
2-0
 inputs) and
monitors all others. In a multiprocessor system with less than six ADSP-2106xs, the unused 
BR
x pins
IRQ
2-0
FLAG
3-0
I/A
I/O/A
T IMEX P
O
HBR
I/A
HBG
I/O
CS
REDY (O/D) O
I/A
DMAR1
DMAR2
DMAG1
DMAG2
BR
6-1
I/A
I/A
O/T
O/T
I/O/S
ID
2-0
I
RPBA
I/S
CPA
 (O/D)
I/O
DT x
DRx
T CLK x
RCLK x
O
I
I/O
I/O