ProASIC3 Device Family Overview
v1.0 1-5
Refer to Figure 1-3 for VersaTile configurations.
User Nonvolatile FlashROM
Actel ProASIC3 devices have 1 kbit of on-chip, user-accessible, nonvolatile FlashROM. The FlashROM
can be used in diverse system applications:
• Internet protocol addressing (wireless or fixed)
• System calibration settings
• Device serialization and/or inventory control
• Subscription-based business models (for example, set-top boxes)
• Secure key storage for secure communications algorithms
• Asset management/tracking
• Date stamping
• Version management
The FlashROM is written using the standard ProASIC3 IEEE 1532 JTAG programming interface. The
core can be individually programmed (erased and written), and on-chip AES decryption can be used
selectively to securely load data over public networks (except in the A3P015 and A3P030 devices),
as in security keys stored in the FlashROM for a user design.
The FlashROM can be programmed via the JTAG programming interface, and its contents can be
read back either through the JTAG programming interface or via direct FPGA core addressing. Note
that the FlashROM can only be programmed from the JTAG interface and cannot be programmed
from the internal logic array.
The FlashROM is programmed as 8 banks of 128 bits; however, reading is performed on a byte-by-
byte basis using a synchronous interface. A 7-bit address from the FPGA core defines which of the 8
banks and which of the 16 bytes within that bank are being read. The three most significant bits
(MSBs) of the FlashROM address determine the bank, and the four least significant bits (LSBs) of
the FlashROM address define the byte.
The Actel ProASIC3 development software solutions, Libero
®
Integrated Design Environment (IDE)
and Designer, have extensive support for the FlashROM. One such feature is auto-generation of
sequential programming files for applications requiring a unique serial number in each part.
Another feature allows the inclusion of static data for system version control. Data for the
FlashROM can be generated quickly and easily using Actel Libero IDE and Designer software tools.
Comprehensive programming file support is also included to allow for easy programming of large
numbers of parts with differing FlashROM contents.
SRAM and FIFO
ProASIC3 devices (except the A3P015 and A3P030 devices) have embedded SRAM blocks along their
north and south sides. Each variable-aspect-ratio SRAM block is 4,608 bits in size. Available memory
configurations are 256×18, 512×9, 1k×4, 2k×2, and 4k×1 bits. The individual blocks have
independent read and write ports that can be configured with different bit widths on each port.
For example, data can be sent through a 4-bit port and read as a single bitstream. The embedded
SRAM blocks can be initialized via the device JTAG port (ROM emulation mode) using the UJTAG
macro (except in A3P015 and A3P030 devices).
Figure 1-3 • VersaTile Configurations
X1
Y
X2
X3
LUT-3
Data Y
CLK
Enable
CLR
D-FF
Data Y
CLK
CLR
D-FF
LUT-3 Equivalent
D-Flip-Flop with Clear or Set
Enable D-Flip-Flop with Clear or Set
