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STANDARD PRODUCT
PM7323 RCMP-200
DATASHEET
PMC-960543
ISSUE 2
ROUTING CONTROL, MONITORING, & POLICING
200 MBPS
Proprietary and Confidential to PMC-Sierra, Inc.
and for its Customer’s Internal Use.
62
9.7
JTAG Test Access Port Interface
The JTAG Test Access Port block provides JTAG support for boundary scan. The
standard JTAG EXTEST, SAMPLE, BYPASS, IDCODE and STCTEST
instructions are supported. The RCMP-200 identification code is 273220CD
hexadecimal.
9.8
Microprocessor Interface
The microprocessor interface is provided for device configuration, control and
monitoring by an external microprocessor. Normal mode registers, test mode
registers and the external SRAM can be accessed through this port. Test mode
registers are used to enhance the testability of the RCMP-200.
The interface has a 16 bit wide data bus. Multiplexed address and data
operation is supported.
9.8.1 SRAM Accesses
Microprocessor access to the external SRAM is provided to allow configuration
and monitoring of individual connections. The VPI/VCI search state machine
allocates a single cycle at the end of each search for microprocessor access.
The maximum time to complete a SRAM access is 2400 ns with a SYSCLK
frequency of 25 MHz. The average completion time is less than 720 ns.Upon
placing the device in stand-by mode (default upon power up), all SRAM cycles
become available to the microprocessor. This allows for rapid configuration of the
device at start-up.
SRAM writes are initiated by writing the values to be presented on the SD[39:0]
and SA[19:0] outputs to the External RAM Data and the External RAM Address
registers. The BUSY status bit and the BUSYB output are asserted until the
actual SRAM access is completed.
SRAM reads are initiated by writing the values to be presented on the SA[19:0]
outputs to the External RAM Address registers. The values read on the SD[39:0]
bus can be read from the External RAM Data registers after the BUSY status bit
and the BUSYB output are deasserted.
The BUSYB output can be connected to a DMA request input of a DMA
controller. The rising edge of BUSYB would initiate the next SRAM access upon
the completion of the current access.