DSM2190F4 STMicroelectronics, DSM2190F4 Datasheet - Page 22

• Manufacturer Part Number: DSM2190F4
• Description: DSM (Digital Signal Processor System Memory) For Analog Devices ADSP-2191 DSPs (3.3V Supply)
• Manufacturer: STMicroelectronics

DSM2190F4
During execution of the Erase cycle, the Flash
memory accepts only Reset and Suspend Sector
Erase instruction sequences. Erasure of one
Flash memory sector may be suspended, in order
to read data from another Flash memory sector,
and then resumed.
The address provided with the initial Flash Sector
Erase command sequence (Table 5) must select
the first desired sector (FS0 - FS7 or CSBOOT0-
CSBOOT3) to erase. Subsequent sector erase
commands that are appended on within the time-
out period must be addressed to other desired
segments (FS0 - FS7 or CSBOOT0-CSBOOT3).
Suspend Sector Erase. When a Sector Erase
cycle is in progress, the Suspend Sector Erase in-
struction sequence can be used to suspend the
cycle by writing 0B0h to any address when an ap-
propriate Sector Select (FS0-FS7 or CSBOOT0-
CSBOOT3) is selected (See Table 5). This allows
reading of data from another Flash memory sector
after the Erase cycle has been suspended. Sus-
pend Sector Erase is accepted only during an
Erase cycle and defaults to Read mode. A Sus-
pend Sector Erase instruction sequence executed
during an Erase time-out period, in addition to sus-
pending the Erase cycle, terminates the time out
period.
The Toggle Flag (DQ6) bit stops toggling when the
device internal logic is suspended. The status of
this bit must be monitored at an address within the
Flash memory sector being erased. The Toggle
Flag (DQ6) bit stops toggling between 0.1 µs and
15 µs after the Suspend Sector Erase instruction
sequence has been executed. The device is then
automatically set to Read mode.
If an Suspend Sector Erase instruction sequence
was executed, the following rules apply:
– Attempting to read from a Flash memory sector
– Reading from a Flash memory sector that was
Table 7. Main Flash Memory Protection Register Definition
Note: Bit Definitions:
Table 8. Secondary Flash Memory Protection/Security Bit Register Definition
Note: Security_Bit = 1, device is secured.
Note: Sec<i>_Prot 1 = Flash memory sector <i> is write protected.
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Bit 7
Sec7_Prot
Bit 7
Security_Bit
that was being erased outputs invalid data.
not being erased is valid.
Sec<i>_Prot 1 = Flash memory sector <i> is write protected.
Sec<i>_Prot 0 = Flash memory sector <i> is not write protected.
Sec<i>_Prot 0 = Flash memory sector <i> is not write protected.
Bit 6
Sec6_Prot
Bit 6
not used
Bit 5
Sec5_Prot
Bit 5
not used
Bit 4
Sec4_Prot
Bit 4
not used
Bit 3
Sec3_Prot
Bit 3
Sec3_Prot
– The Flash memory cannot be programmed, and
– If a Reset Flash instruction sequence is re-
Resume Sector Erase. If a Suspend Sector
Erase instruction sequence was previously exe-
cuted, the erase cycle may be resumed with this
instruction sequence. The Resume Sector Erase
instruction sequence consists of writing 030h to
any address while an appropriate Sector Select
(FS0-FS7 or CSBOOT0-CSBOOT3) is active.
(See Table 5.)
Flash Memory Sector Protect.
Each Flash memory sector can be separately pro-
tected against Program and Erase cycles. Sector
Protection provides additional data security be-
cause it disables all Program or Erase cycles. This
mode can be activated through the JTAG Port or a
Device Programmer. Sector protection can be se-
lected for each sector using PSDsoft Express.
This automatically protects selected sectors when
the device is programmed through the JTAG Port
or a Device Programmer. Flash memory sectors
can be unprotected to allow updating of their con-
tents using the JTAG Port or a Device Program-
mer. The DSP can read (but cannot change) the
sector protection bits.
Any attempt to program or erase a protected Flash
memory sector is ignored by the device. The Verify
operation results in a read of the protected data.
This allows a guarantee of the retention of the Pro-
tection status.
The sector protection status can be read by the
DSP through the Main Flash memory protection
register (in the csiop block) as defined in Table 7,
and Secondary Flash memory protection register
in Table 8.
only responds to Resume Sector Erase and Re-
set Flash instruction sequences (Read is an op-
eration and is allowed).
ceived, data in the Flash memory sector that
was being erased is invalid.
Bit 2
Sec2_Prot
Bit 2
Sec2_Prot
Bit 1
Sec1_Prot
Bit 1
Sec1_Prot
Bit 0
Sec0_Prot
Bit 0
Sec0_Prot