PM7340 S/UNI-IMA-8
PRELIMINARY
INVERSE MULTIPLEXING OVER ATM
DATA SHEET
PMC-2001723
ISSUE 3
INVERSE MULTIPLEXING OVER ATM
3. The ICP cell data content is copied to the ICP cell buffer registers.
4. The PM_ICP_AVL bit is set, this will cause an ICP_CELL_AVL_INT.
5. To read the ICP cell, the lock bit must be set by writing ‘1’ to the
ICP_FWD_LOCK_REQ bit in the ICP forwarding control register. Once the
lock is granted when the ICP_FWD_LOCK_GRANT bit read back as ‘1’. The
lock bit must be set prior to clearing the interrupt, otherwise it is possible to
have multiple interrupt generated.
6. The interrupt should be cleared by reading the ICP cell forwarding status
register.
7. The data may be readout from Forwarding ICP cell buffer registers.
8. The ICP_FWD_LOCK_REQ should be cleared bit by writing to the register
location.
12.6.2 SDRAM Diagnostic access
Diagnostic access of the external SDRAM is provided to enable SDRAM testing.
The access to the SDRAM is provided on a cell buffer granularity. Each cell
buffer is 64 bytes. By providing cell buffer burst access to the SDRAM, the
SDRAM diagnostic accesses utilize the same burst access timing as is used
when the S/UNI-IMA-8 is operating.
Prior to performing any diagnostic accesses to the SDRAM, the SDRAM
interface must be placed in diagnostic mode. In diagnostic mode, all automatic
accesses from the S/UNI-IMA-8 (except refresh) are disabled and all accesses
are controlled via the microprocessor interface.
To write to the SDRAM, first the image of the cell must be written into the
SDRAM DIAG Burst-Write RAM using the SDRAM DIAG Burst RAM Indirect
Access. Once the image of the cell has been written, a command to transfer the
data into the external SDRAM should be issued using the SDRAM DIAG WRITE
CMD registers. The SDRAM DIAG WRITE CMD registers specify the address of
the cell buffer to be written in the external SDRAM.
For a read operation, a read command is issued using the SDRAM DIAG READ
CMD registers. This command transfers data from the SDRAM into the internal
cell buffer. When the command is complete as indicated by the RDBUSY bit in
the command register, the data may be read out of the cell buffer using the
SDRAM DIAG Burst RAM indirect access.
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
281
PMC [ PMC-SIERRA, INC ]
