ST72P314J2T View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
ST72P314J2T
STMicroelectronics
'ST72P314J2T' PDF : 153 Pages View PDF
ST72334J/N, ST72314J/N, ST72124J
2.4 FLASH PROGRAM MEMORY
2.4.1 Introduction
Flash devices have a single voltage non-volatile
FLASH memory that may be programmed in-situ
(or plugged in a programming tool) on a byte-by-
byte basis.
2.4.2 Main features
s Remote In-Situ Programming (ISP) mode
s Up to 16 bytes programmed in the same cycle
s MTP memory (Multiple Time Programmable)
s Read-out memory protection against piracy
2.4.3 Structural organisation
The FLASH program memory is organised in a
single 8-bit wide memory block which can be used
for storing both code and data constants.
The FLASH program memory is mapped in the up-
per part of the ST7 addressing space (F000h-
FFFFh) and includes the reset and interrupt user
vector area .
2.4.4 In-Situ Programming (ISP) mode
The FLASH program memory can be programmed
using Remote ISP mode. This ISP mode allows
the contents of the ST7 program memory to be up-
dated using a standard ST7 programming tools af-
ter the device is mounted on the application board.
This feature can be implemented with a minimum
number of added components and board area im-
pact.
An example Remote ISP hardware interface to the
standard ST7 programming tool is described be-
low. For more details on ISP programming, refer to
the ST7 Programming Specification.
Remote ISP Overview
The Remote ISP mode is initiated by a specific se-
quence on the dedicated ISPSEL pin.
The Remote ISP is performed in three steps:
– Selection of the RAM execution mode
– Download of Remote ISP code in RAM
– Execution of Remote ISP code in RAM to pro-
gram the user program into the FLASH
Remote ISP hardware configuration
In Remote ISP mode, the ST7 has to be supplied
with power (VDD and VSS) and a clock signal (os-
cillator and application crystal circuit for example).
This mode needs five signals (plus the VDD signal
if necessary) to be connected to the programming
tool. This signals are:
– RESET: device reset
– VSS: device ground power supply
– ISPCLK: ISP output serial clock pin
– ISPDATA: ISP input serial data pin
– ISPSEL: Remote ISP mode selection. This pin
must be
board
connected
to
VSS
on
the
application
If any of these pins are used for other purposes on
the application, a serial resistor has to be imple-
mented to avoid a conflict if the other device forces
the signal level.
Figure 6 shows a typical hardware interface to a
standard ST7 programming tool. For more details
on the pin locations, refer to the device pinout de-
scription.
Figure 6. Typical Remote ISP Interface
XTAL
HE10 CONNECTOR TYPE
TO PROGRAMMING TOOL
1
CL0
CL1
ST7
ISP SEL
VSS
RESET
IS PCLK
ISP DATA
10kΩ
4.7kΩ
APPLIC ATION
2.5 Program Memory Read-out Protection
The read-out protection is enabled through an op-
tion bit.
For FLASH devices, when this option is selected,
the program and data stored in the FLASH memo-
ry are protected against read-out piracy (including
a re-write protection). When this protection option
is removed the entire FLASH program memory is
first automatically erased.
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