psd813f1a STMicroelectronics, psd813f1a Datasheet - Page 6

• Manufacturer Part Number: psd813f1a
• Description: Flash In-system Programmable Isp Peripherals For 8-bit Mcus, 5 V
• Manufacturer: STMicroelectronics

PSD813F1A
SUMMARY DESCRIPTION
The PSD family of Programmable Microcontroller
(MCU) Peripherals brings In-System Programma-
bility (ISP) to Flash memory and programmable
logic. The result is a simple and flexible solution for
embedded designs. PSD devices combine many
of the peripheral functions found in MCU based
applications.
PSD devices integrate an optimized “microcon-
troller macrocell” logic architecture. The Macrocell
was created to address the unique requirements
of embedded system designs. It allows direct con-
nection between the system address/data bus and
the internal PSD registers to simplify communica-
tion between the MCU and other supporting devic-
es.
The PSD family offers two methods to program
PSD Flash memory while the PSD is soldered to a
circuit board.
In-System Programming (ISP) via JTAG
An IEEE 1149.1 compliant JTAG interface is in-
cluded on the PSD enabling the entire device
(Flash memory, EEPROM, the PLD, and all con-
figuration) to be rapidly programmed while sol-
dered to the circuit board. This requires no MCU
participation, which means the PSD can be pro-
grammed anytime, even while completely blank.
The innovative JTAG interface to Flash memories
is an industry first, solving key problems faced by
designers and manufacturing houses, such as:
First time programming. How do I get firmware
into the Flash the very first time? JTAG is the an-
swer, program the PSD while blank with no MCU
involvement.
Inventory build-up of pre-programmed devic-
es. How do I maintain an accurate count of pre-
programmed Flash memory and PLD devices
based on customer demand? How many and what
version? JTAG is the answer, build your hardware
with blank PSDs soldered directly to the board and
then custom program just before they are shipped
to customer. No more labels on chips and no more
wasted inventory.
Expensive sockets. How do I eliminate the need
for expensive and unreliable sockets? JTAG is the
answer. Solder the PSD directly to the circuit
board. Program first time and subsequent times
with JTAG. No need to handle devices and bend
the fragile leads.
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In-Application Programming (IAP)
Two independent memory arrays (Flash and EE-
PROM) are included so the MCU can execute
code from one memory while erasing and pro-
gramming the other. Robust product firmware up-
dates in the field are possible over any
communication channel (CAN, Ethernet, UART,
J1850, etc.) using this unique architecture. De-
signers are relieved of these problems:
Simultaneous read and write to Flash memo-
ry. How can the MCU program the same memory
from which it is executing code? It cannot. The
PSD allows the MCU to operate the two memories
concurrently, reading code from one while erasing
and programming the other during IAP.
Complex memory mapping. I have only a 64K-
byte address space to start with. How can I map
these two memories efficiently? A Programmable
Decode PLD is the answer. The concurrent PSD
memories can be mapped anywhere in MCU ad-
dress space, segment by segment with extremely
high address resolution. As an option, the second-
ary Flash memory can be swapped out of the sys-
tem memory map when IAP is complete. A built-in
page register breaks the 64K-byte address limit.
Separate program and data space. How can I
write to Flash or EEPROM memory while it resides
in “program” space during field firmware updates,
my MCU won’t allow it! The Flash PSD provides
means to “reclassify” Flash or EEPROM memory
as “data” space during IAP, then back to “program”
space when complete.
PSDsoft Express
PSDsoft Express, a software development tool
from ST, guides you through the design process
step-by-step making it possible to complete an
embedded MCU design capable of ISP/IAP in just
hours. Select your MCU and PSDsoft Express
takes you through the remainder of the design with
point and click entry, covering PSD selection, pin
definitions, programmable logic inputs and out-
puts, MCU memory map definition, ANSI-C code
generation for your MCU, and merging your MCU
firmware with the PSD design. When complete,
two different device programmers are supported
directly from PSDsoft Express: FlashLINK (JTAG)
and PSDpro.