// ram test in bootrom
/*
RAM Test (MBIST) and RAM Initialization
The RAM memory test is performed for cold reset type.
The RAM initialization is performed for cold and warm reset types.
When executed, the RAM MBIST test destroys the contents of the tested RAM.It consists of a linear write/read
algorithm using alternating data.
In case an error is detected in the RAM MBIST, the appropriate error status is captured and the device enters
an endless loop. As the watchdog is enabled when entering the endless error loop after a boot in user or
debugmode, a WDT1 cold reset is asserted after timeout and the RAM test is re-executed.
After five (5) consecutive watchdog resets, the device enters SLEEP mode (by hardware function).
The RAM initialization writes the whole RAM to zero with the proper ECC status. This is needed to prevent an
ECC error during user code execution due to a write operation to a non initialized location (with invalid ECC
code).
Note: The standard RAM interface is disabled during MBIST test execution.
在bootrom中的ram測試
包括RAM測試（MBIST） 和RAM 初始化兩種
RAM記憶測試執行於冷復位類型。
RAM初始化執行於冷和熱復位類型。
當執行時，RAM MBIST測試破壞了測試的RAM的內容。它包含了一個線性的寫/讀算法用於交互數據。
假如一個錯誤在RAM MBIST中被檢測到，適當的錯誤狀態被捕獲到，然後設備進入
一個無盡循環中。當在引導用戶或調試模式之後進入無休止的錯誤循環時，看門狗被啓用。
在超時後一個WDT1冷復位生效並且RAM測試被重新執行。
在5次連續的看門狗復位之後，設備進入SLEEP模式（使用硬件功能）。
RAM的初始化使用適當的ECC狀態來將整個RAM寫成零。
由於對非初始化位置的寫保護（使用無效的ECC代碼），在執行代碼時，需要防止ECC錯誤。
注意：在MBIST測試執行時標準的RAM接口被禁用。