MAXQ7665BATM+ Maxim Integrated Products, MAXQ7665BATM+ Datasheet - Page 33

• Manufacturer Part Number: MAXQ7665BATM+
• Description: IC MCU-BASED DAS 16BIT 48-TQFN
• Manufacturer: Maxim Integrated Products
• Series: MAXQ™r

Specifications of MAXQ7665BATM+

• Core Processor: RISC
• Core Size: 16-Bit
• Speed: 8MHz
• Connectivity: CAN, LIN, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 8
• Program Memory Size: 64KB (32K x 16)
• Program Memory Type: FLASH
• Ram Size: 256 x 16
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.25 V
• Data Converters: A/D 8x12b, D/A 1x12b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 48-TQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

Following any reset, execution begins in the utility
ROM. The ROM software determines whether the pro-
gram execution should immediately jump to location
0000h, the start of user-application code, or to one of
the special routines mentioned. Routines within the utili-
ty ROM are user-accessible and can be called as sub-
routines by the application software. More information
on the utility ROM contents is contained in the
MAXQ7665/MAXQ7666 User’s Guide .
Some applications require protection against unautho-
rized viewing of program code memory. For these
applications, access to in-system programming, in-
application programming, or in-circuit debugging func-
tions is prohibited until a password has been supplied.
The password is defined as the 16 words of physical
program memory at addresses 0010h to 001Fh.
A single password lock (PWL) bit is implemented in the
SC register. When the PWL is set to one (POR default),
the password is required to access the utility ROM,
including in-circuit debug and in-system programming
routines that allow reading or writing of internal memo-
ry. When PWL is cleared to zero, these utilities are fully
accessible without the password. The password is
automatically set to all ones following a mass erase.
The flash memory of the µC can be programmed by
two different methods: in-system programming and in-
application programming. Both methods afford great
flexibility in system design as well as reduce the life-
cycle cost of the embedded system. These features
can be password protected to prevent unauthorized
access to program memory.
An internal bootstrap loader allows the device to be
reloaded over a simple JTAG interface. As a result,
software can be upgraded in-system, eliminating the
need for a costly hardware retrofit when updates are
required. Remote software uploads are possible that
enable physically inaccessible applications to be fre-
quently updated. The interface hardware can be a
JTAG connection to another µC, or a connection to a
PC serial port using a serial-to-JTAG converter such as
the MAXQJTAG-001, available from Maxim Integrated
Products, Inc. If in-system programmability is not
required, a commercial gang programmer can be used
for mass programming.
______________________________________________________________________________________
In-System Programming
16-Bit RISC Microcontroller-Based
Smart Data-Acquisition Systems
Programming
After a power-up or reset, the JTAG interface is active
and loading the TAP with the system programming
instruction invokes the bootstrap loader. Setting the SPE
bit to 1 during reset through the JTAG interface executes
the bootstrap-loader-mode program that resides in the
utility ROM. When programming is complete, the boot-
strap loader can clear the SPE bit and reset the device,
allowing the device to bypass the utility ROM and begin
execution of the application software.
The following bootstrap loader functions are supported:
• Load
• Dump
• CRC
• Verify
• Erase
The in-application programming feature allows the µC to
modify its own flash program memory while simultane-
ously executing its application software. This allows on-
the-fly software updates in mission-critical applications
that cannot afford downtime. Alternatively, it allows the
application to develop custom loader software that can
operate under the control of the application software.
The utility ROM contains user-accessible flash program-
ming functions that erase and program flash memory.
These functions are described in detail in the
MAXQ7665/MAXQ7666 User’s Guide for these devices.
Most functions of these devices are controlled by sets of
registers. These registers provide a working space for
memory operations as well as configuring and address-
ing peripheral registers on the device. Registers are
divided into two major types: system registers and
peripheral registers. The common register set, also
known as the system registers, includes the ALU, accu-
mulator registers, data pointers, interrupt vectors and
control, and stack pointer. The peripheral registers
define additional functionality that may be included by
different products based on the MAXQ architecture. This
functionality is broken up into discrete modules so that
only the features required for a given product need to be
included. Tables 2 and 4 show the MAXQ7665A–
MAXQ7665D register set. Tables 3 and 5 show the bit
functions and reset values.
In-Application Programming
Register Set
33