MAXQ8913 Maxim, MAXQ8913 Datasheet - Page 18

• Manufacturer Part Number: MAXQ8913
• Description: The MAXQ8913 is a single-chip servo controller designed as a complete solution for dual axis optical image stabilization (OIS) applications
• Manufacturer: Maxim

16-Bit, Mixed-Signal Microcontroller with Op Amps,
ADC, and DACs for All-in-One Servo Loop Control
On reset, the stack pointer, SP, initializes to the top of
the stack (0Fh). The CALL, PUSH, and interrupt-vector-
ing operations increment SP, then store a value at the
location pointed to by SP. The RET, RETI, POP, and
POPI operations retrieve the value at SP and then
decrement SP.
The utility ROM is a 4KB block of internal ROM memory
that defaults to a starting address of 8000h. The utility
ROM consists of subroutines that can be called from
application software. These include the following:
• In-system programming (bootstrap loader) using
• In-circuit debug routines
• Test routines (internal memory tests, memory loader,
• User-callable routines for in-application flash pro-
Following any reset, execution begins in the utility ROM.
The ROM software determines whether the program
execution should immediately jump to location 0000h,
the start of user-application code, or to one of the spe-
cial routines mentioned. Routines within the utility ROM
are user accessible and can be called as subroutines
by the application software. More information on the
utility ROM contents is contained in the MAXQ Family
User’s Guide: MAXQ8913 Supplement .
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 (power-on
reset default) and the contents of the memory at
addresses 0010h to 001Fh are any value other than FFh
or 00h, the password is required to access the utility
ROM, including in-circuit debug and in-system pro-
gramming routines that allow reading or writing of inter-
nal memory. When PWL is cleared to zero, these
utilities are fully accessible without password. The
password is automatically set to all ones following a
mass erase.
The flash memory of the microcontroller can be pro-
grammed by two different methods: in-system program-
ming and in-application programming. Both methods
afford great flexibility in system design as well as
18
JTAG interface
etc.)
gramming and fast table lookup
______________________________________________________________________________________
Programming
Utility ROM
reduce the life-cycle cost of the embedded system.
These features can be password protected to prevent
unauthorized access to code 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 updates enable application
updates to physically inaccessible equipment. The
interface hardware can be a JTAG connection to anoth-
er microcontroller or a connection to a PC serial port
using a serial-to-JTAG converter such as the
MAXQJTAG-001, available from Maxim. If in-system
programmability is not required, a commercial gang
programmer can be used for mass programming.
Activating the JTAG interface and loading the test
access port (TAP) with the system programming instruc-
tion 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 bootstrap
loader can clear the SPE bit and reset the device, allow-
ing the device to bypass the utility ROM and begin exe-
cution of the application software.
The following bootstrap loader functions are supported:
• Load
• Dump
• CRC
• Verify
• Erase
The in-application programming feature allows the
microcontroller to modify its own flash program memory
while simultaneously executing its application software.
This allows on the fly software updates in mission-criti-
cal applications that cannot afford downtime.
Alternatively, it allows the application to develop cus-
tom loader software that can operate under the control
of the application software. The utility ROM contains
user-accessible flash programming functions that erase
and program flash memory. These functions are
described in detail in the MAXQ Family User’s Guide:
MAXQ8913 Supplement .
Most functions of the device 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
(Bootloader) In-System Programming
In-Application Programming
Register Set