Ram Verification - Renesas RL78 Series Application Note

RL78 Family
3.2.1 Power- Up Tests
All the ROM memory used must be tested at power up. Both hardware and software CRC modules are
capable of calculating the CRC value over the whole memory range.
3.2.2 Periodic
It is suggested that the periodic testing of Flash memory is done in stages, depending on the time available to
the application. The application will need to save the partially calculated result if using the software module.
This value can then be set as starting point for the next stage of the CRC calculation.
When using the hardware peripheral unit, the partial CRC result value could be left in the result register of
the hardware CRC peripheral unit, but it is advised to save this value and compare it before starting the next
part of the calculation.
In this way all of the Flash memory can be verified in time slots convenient to the application.

3.3 RAM Verification

When verifying the RAM it is important to remember the following points:
1. RAM being tested can not be used for anything else including the current stack.
2. Any test requires a RAM buffer where memory contents can be safely copied to and restored from.
3. The stack area cannot be tested after the system has been initialised, unless the content is relocated to a new
area and the stack pointer changed accordingly. Interrupts should not be serviced during this operation.
3.3.1 Power-Up
It is recommended to use the "initial Ram test modules (march C or March X), as these are specifically
design for testing all of the Ram area at power on or Reset. The modules have been designed without any
function call and so are suitable to be executed before the system and
contents of the Ram memory will be destroyed.
3.3.2 Periodic
Periodic testing of the Ram memory is usually done in small stages, depending on the time available to the
application and the available space necessary to buffer the system Ram contents during testing. Each stage
provides a pass / fail status over the range specified, in this way all of the Ram memory can be verified time
slots convenient to the application.
R01AN0749EG0201 Rev.2.01
Mar 04, 2014
VDE Certified IEC60730/60335 Self Test Library
C-Stack are initialised as any
Page 29 of 50