PM7311 pmc-sierra, PM7311 Datasheet - Page 86

• Manufacturer Part Number: PM7311
• Description: Freedm 84a1024l Assp Telecom Standard Datasheet
• Manufacturer: pmc-sierra

Proprietary and Confidential to PMC-Sierra, Inc., and for its customers’ internal use.
Document No.: PMC-2021832, Issue 2
10.9.12
Figure 30 DRAM Configuration for the Re-Sequencing Memory Interface
SRAMC
The external context memory holds data that needs to be accessed by a number of internal blocks.
The role of the SRAMC block is to arbitrate these accesses. The Connection context memory
supports the frame building block, TFRAG, and IQM-12.
The SRAMC supports glueless access to 1, 2 or 4 banks of Pipelined ZBT-compatible
Standard SRAM. When FREEDM 84A1024L is configured to interface to Standard or ZBT-
compatible SSRAM, CCBSELB is the inverse of CCADD[16]. CCBSELB and CCADD[16:17]
are used to select 4 banks when 64Kx36 devices are used (see Figure 31). It should be noted that
maximum performance is achieved with ZBT SSRAMs. Standard SSRAMs will degrade chip
performance by approximately 20%.
1
·
·
·
The ZBT-compatible SRAM family includes:
ZBT, short for Zero Bus Turnaround, manufactured by IDT, Micron and Motorola,
NoBL, short for No Bus Latency, manufactured by Cypress, and
Nt , short for No turnaround, manufactured by Samsung
FREEDM336A1024
(100 MHz)
SYSCLK
RSADD[12:0]
RSDAT[31:0]
RSBS[1:0]
RSRASB
RSCASB
SYSCLK
RSWEB
RSCSB
FREEDM 84A1024L ASSP Telecom Standard Product Data Sheet
"1"
"1"
RSCSB
RSRASB
RSCASB
RSWEB
RSBS[1:0]
RSADD[12:0]
RSDAT[15:0]
CKE
SYSCLK
RSCSB
RSRASB
RSCASB
RSWEB
RSBS[1:0]
RSADD[12:0]
RSDAT[15:0]
CKE
SYSCLK
1
or
Released
SDRAM A
SDRAM B
256 Mbit
256 Mbit
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