Intel C2550 FH8065401488912 Fiche De Données
Codes de produits
FH8065401488912
Volume 2—Serial Peripheral Interface (SPI)—C2000 Product Family
Flash Access
Intel
®
Atom™ Processor C2000 Product Family for Microserver
Datasheet, Vol. 2 of 3
September 2014
480
Order Number: 330061-002US
22.6.2
Program Register Access
• Reads, writes, and erases are all supported.
• Program register access uses hardware or software sequencing. See
• Program register access uses hardware or software sequencing. See
for further information.
• Program register accesses are not allowed to cross a 4-KB boundary and do not
issue a command that extends across two components.
• The software programs the FLA corresponding to the region desired.
— The software must read the devices primary region base/limit address to create
an FLA.
Each internal initiator accesses the Flash through a set of memory-mapped registers
that are dedicated to each Flash device.
The software uses two separate control and status registers when using program
register access to the Flash. The hardware sequencing control/status registers rely on
the hardware to issue the appropriate Flash instructions and atomic sequences. The
software sequencer puts control into the hands of the software for what instructions to
issue and when.
The goal is to support all Flash components through hardware sequencing. Software
sequencing is intended only as a back-up strategy.
Note:
Software sequencing is required when operating in a non-descriptor mode.
22.6.2.1
Security
• Only the CPU core running the BIOS accesses the registers.
• Using the protected range registers, the BIOS adds separate read/write protection
• Using the protected range registers, the BIOS adds separate read/write protection
above that granted in the Flash Descriptor for its own accesses.
— For example, the BIOS wants to protect different regions of the BIOS from
being erased.
— Ranges extend across region boundaries.