SPRUJB3 March 2024 AM67 , AM67A , TDA4AEN-Q1 , TDA4VEN-Q1
When less data is written than defined by the element size for the ring for RING or MESSAGE modes, only the written data is stored in the memory and any remaining bytes maintain their old values. The index and occ are still incremented normally, and any special fields that are unwritten are assumed to be 0 (such as the length for QM mode rings).
Writing less data for CREDENTIALS mode is illegal, as those types need the full data to append the additional words to the correct offsets in memory.
When more data is written than defined by the element size for the ring, it will be an error and the write will be ignored and no index or occ increments occur. The only exception is for writes to an 8 byte element size ring, where the additional fields up to another 8 bytes are allowed but not written (for old Queue Manager compatibility).
When less data is read than defined by the element size for the ring, only the read data is fetched from memory, and any remaining bytes are lost. The index and occ are still incremented normally.
When more data is read than defined by the element size for the ring, it will be an error and the read will not affect the ring, the read data will be 0s, and no index or occ decrements occur. Access beyond the credentials word should not be attempted and can result in unpredictable behavior.
All accesses must be for multiples of 32 bit words, and partial bytes are not supported for all ring modes.