SST39VF400A-70-4C-MAQE-T Microchip Technology, SST39VF400A-70-4C-MAQE-T Datasheet - Page 8

• Manufacturer Part Number: SST39VF400A-70-4C-MAQE-T
• Description: 2.7V To 3.6V 4Mbit Multi-Purpose Flash 48 WFBGA 4x6x0.8 Mm T/R
• Manufacturer: Microchip Technology
• Series: -r

Specifications of SST39VF400A-70-4C-MAQE-T

• Format - Memory: FLASH
• Memory Type: FLASH
• Memory Size: 4M (256K x 16)
• Speed: 70ns
• Interface: Parallel
• Voltage - Supply: 2.7 V ~ 3.6 V
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 48-WFBGA
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Application Note
Software Comparisons
The SST 39 series and AT49 series devices use the same
command set for Byte-Program, Chip-Erase, Read-ID, and
Reset operation as described in the table below.
TABLE 11: C
The primary difference between SST and Atmel is the Sec-
tor-Erase operation, which is not offered by the AT49 series
products. Atmel has a boot block of 8 KByte, and a single
block comprising the remainder of the memory (like 248
KByte for 49F020), and they only support Chip-Erase. SST,
on the other hand, has uniform 4 KByte sectors. As a
result, a SST 39 series device can use the same software
as the corresponding AT49F device, since SST 39 series
devices offer both Sector-Erase and Chip-Erase, if the boot
block is not protected.
Some Atmel designs may protect this 8 KByte sector, so
that, during Chip-Erase, this sector is not erased with the
other block. If this feature is enabled, then the software
would have to be modified to do Sector-Erase operations
on the SST device in place of the Chip-Erase on the pro-
tected Atmel device, so that the sectors corresponding to
the boot block are not erased. An alternative is to erase the
entire chip, and then re-program the two SST sectors cor-
responding to the Atmel boot block.
Note that although the above notes describe the difference
between 5V flash from Atmel and SST, identical compari-
sons are valid for describing the 3V flash from Atmel and
SST. Consequently, the SST’s 39 series flash can be used
to substitute Atmel equivalents with minimal design
changes.
©2005 Silicon Storage Technology, Inc.
Command
Byte-Program
Chip-Erase
Sector-Erase
Software Exit
ID/Reset
Read-ID
Boot block
lockout
OMMAND
SST
4-Byte
6-Byte
6-Byte
1 or 3-Byte
3-Byte
Not supported
S
EQUENCE
C
OMPARISONS
ATME;
Same
Same
Not supported
Same
Same
6-Byte
Multi-Purpose Flash (39 Series) Byte-wide Products
T11.0 2014
8
Comparisons with the AT49LV008A
For 8M, Atmel offers the AT49LV008A. This device reads,
programs, and erases with a single 2.7-3.6V power supply
voltage.
Hardware Comparisons
The SST39VF080 and Atmel’s AT49LV008A are offered in
JEDEC standard 10mm x 20mm 40-lead TSOP packages
and have the same pin assignments for basic functions.
SST also offers this product in a BGA package with the
same ball assignments as Atmel. The only differences in
pin assignments between these two products are on pins
10 and 12, as described in the following table.
TABLE 12: P
The AT49LV008A has a hardware reset function (RESET#)
on pin 12 whereas the SST39VF080 has a no-connect on
this pin. The purpose of RESET# is to terminate any opera-
tion in progress and reset the internal state machine to
read array data. The only difference is that in SST’s case,
an Erase or Program operation is allowed to complete,
whereas in the case of the competitor, such an operation is
interrupted by the RESET# command. The system would
have to wait for SST’s operation to complete before it can
read. Since SST has faster Erase and Program times, wait-
ing is not an issue.
The Ready/Busy pin (RY/BY#) on the Atmel device pro-
vides an additional hardware method of detecting comple-
tion of a Program or Erase cycle. In the case of Atmel, the
RY/BY# pin is necessary because Atmel has an internal
state machine that varies the length of the Write pulse
width. SST, on the other hand, uses a fixed pulse width to
program and erase its devices. As a result, SST does not
require a RY/BY# pin and does not offer it.
In summary, an SST39VF080 can be used on an existing
AT49LV008A-based design without any board layout
changes when used in x16 mode.
Software Comparisons
The SST39VF080 uses the JEDEC standard command
set for x16 single-power-supply flash memory while the
AT49LV008A uses JEDEC-compatible command sets. The
command sequences for basic device operations between
the two products are identical. For more details, please
refer to the data sheet of each product.
Pin 12
Pin 15
1. No connect
IN
SST
NC
NC
D
IFFERENCES
1
Designing In SST’s
ATMEL
RESET#
RY/BY#
S72014-04-000
T12.0 2014
10/05