Device supports the 1S-1S-1S mode of
OPSI configuration. This means that command, address, and data access are in single
bit mode. The Command and Address issued are 8 bits and 24 bits followed by 8 dummy cycles. 50 MHz is the supported frequency of
operation.
OSPI
(1S) Module Configuration:
- OSPI has two associated
memory regions, the first memory region is dedicated to the configuration
port i.e all internal registers can be programmed and serial transfers made
from the supported external OSPI flash devices. Configuration region is
available at 0x5380_8000 in the SoC address map.
- The second memory region is associated mainly with the memory-mapped port and is used for communication directly with external flash devices, the memory region starts at 0x6000_0000. Code will be copied from this region to internal RAM and then execution starts.
- Serial data clock is derived
from the clock source “SYS_CLK” (200MHz). This clock is divided by a factor
4 and results in a 50MHz interface clock.
- MODE3 of OSPI clock mode is
used, Clock phase and polarity are set to 1, when data is not being
transferred SCK=1, data shifted on falling edge and input on rising
edge.
ROM Sequence:
- Command issued by ROM in this mode is 0x0B.
- RBL looks for SBL image at
address 0x0000_0000, in case of boot failures due to corrupted image or any
other reason, RBL tries to boot with redundant image placed as explained in
the section Redundant boot
support
.
Flash Dependency:
- RBL does not perform any
specific action to detect, reset, or power up the OSPI device. OSPI is
assumed to be properly powered and reset completed before every attempt to
boot by RBL.