Datasheet

Memory Subsystem
Intel
®
Quark™ microcontroller D2000
Datasheet January 2016
118 Document Number: 333577-002EN
Producer
Consumer
Data
Flag
Analysis
LMT DMA
SRAM SRAM
DTCM writes from LMT are in-order
and in program order. Si
nce AHB
fabric is in-
order, DMA reads will
observe data in same order. Hence,
no memory consistency concerns.
SRAM
AHB, LMT
Interrupt
There is no posting buffer in SRAM
controller on DTCM interface. LMT
ensures DTCM write completes
before AHB write (to DMA) is issued.
Hence, DMA read will receive
consistent data when it reads SRAM
via AHB.
AHB SRAM
LMT ensures AHB write completes
before DTCM write is issued. Hence,
DMA read will receive consistent
data when it reads data on AHB.
AHB
AHB, LMT
Interrupt
Since LMT writes to AHB are in-order
and in program order, there is no
memory consistency concern.
LMT LMT
SRAM
SRAM,
LMT
Interrupt
LMT is self-consistent.
SRAM AHB
LMT ensures DTCM write completes
before AHB write is issued.
AHB SRAM
LMT ensures AHB write completes
before DTCM write is issued.
AHB
AHB, LMT
Interrupt
Since LMT writes to AHB are in-order
and in program order, there is no
memory consistency concern.
Write to flash memory write has a very restricted use model. Flash write can be
performed for following use cases since SRAM is used for updating run-time data by an
application:
• Initialize code (e.g. boot code) after manufacturing,
• Update FW
• Load App
Only LMT can initiate a write to Flash memory via a sequence of register writes to Flash
Configuration registers. The only two interesting cases are:
• Handling of SW breakpoint: SW tool chain must perform following sequence of
operations:
o Copy the appropriate 2K page (that contains the set of instructions to be
modified) from Flash memory to SRAM.
o Copy the original set of instructions in SRAM to a temporary location (for
later restoration) in SRAM
o Update 2K page in SRAM with new instructions
o Erase the 2KB page in Flash
o In a loop, program flash memory 32b at a time.
o When the loop completes, flash memory has updated 2K page.