Renesas Single-Chip Microcomputer M306NKT3 - Manual (Page 32)

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3.2.2 What is the difference between Boot Mode and User Mode?
The Renesas Flash devices have different modes of operation which are controlled by the state of the
mode pins when the device is brought out of reset. Most devices have an asynchronous serial Boot
Mode and a User/User Program Mode.
Generally, (asynchronous serial) Boot Mode connections, start with an autobaud – sending
synchronisation data packets to setup initial communications at a given baud rate. Additionally, for
most devices, the entire flash will be erased as part of the connection process, thus preventing any
Intellectual Property held on the device from being read from Boot Mode.
For a User Mode connection, the device must already be programmed with some code which talks to
FDT and allows programming. Most kernels are supplied with a User Mode micro kernel and test
program (*usually called “uGenU.mot” and “xxxxtest.mot”). These files provide a
demonstration of User Mode programming and must be programmed into the device and be executing
before FDT tries to connect in User Mode. User Mode does not normally force an erase of the flash
during the connection process and does not autobaud to setup initial communications. The
demonstration User Mode test programs have the required Bit Rate Register value compiled into them
for setting up initial communications at 9600 baud; hence User Mode kernels need to be rebuilt for
different clock frequencies.
*Note that where the files are to be used as part of an embedded monitor, the User Mode kernel files may be also output as
binary files (.cde) without the reset vector populated. Some kernels use only a single file for the User Mode test program (e.g.
Protocol C kernels).
3.2.3 What is the difference between User Mode and User Program Mode?
Some devices use an additional mode pin to protect the flash from being written or erased by mistake;
this pin is normally known as the “Flash Write Enable” pin (FWE) if it has to be logic high to allow
programming, or the “Flash Write Protect” pin (FWP) if it has to be logic low to allow programming.
For these devices, this pin distinguishes “User Mode” from “User Program Mode”. An FDT User Mode
connection expects the device to be in User Program Mode at the point of programming and erasing,
and if using the FDM, can reset the device into User Mode to execute the programmed code on
disconnection.
3.2.4 What are “Protocol A”, “Protocol B”, “Protocol C” and “Protocol D” Kernels?
“Protocol A” - For some 0.8
μm, 0.6μm and 0.35μm flash devices using FDT 1.5 style kernels.
These are legacy kernels that are not supported and not included in the FDT installer. Protocol
A kernels are not available in the Japanese versions of FDT. Protocol A kernels support use of
the UPB but not the FDM. The kernel needs to be rebuilt for different crystal frequencies in
Boot and User Modes, and for changing the PMODE pin if using the UPB. Please refer to the
documentation supplied with the kernels for additional information.
“Protocol B” – For 0.35
μm devices. These support the FDM but not the UPB.
Boot Mode - The kernel (made up of the Boot Mode Micro Kernel, Boot Mode Main Kernel,
and the Write and Erase modules) is held on the PC and downloaded as required. The Boot
Mode kernel does not need to be rebuilt for different crystal frequencies; this information is
stored in the FDT project and downloaded at runtime and initial communication is achieved by
the autobaud (where FDT sends 0x00 data until the device synchronises with it).
User Mode – The User Mode Test Program and User Mode Micro-Kernel need to be already
programmed and executing on the device. The initial Bit Rate Register value is held in the