5.3.4 .asciz “string₁” | <##>₁ [, ..., “string_n” | <##>_n]

Assembles each string with an automatic trailing zero byte or <##> into successive bytes in the current section.

Note: If the ## is not a number, 0 will be assembled. If the ## is greater than 255, then the value will be truncated to a byte.

If in a code (executable) section, the upper program memory byte will be filled with the last .fillupper value specified or the NOP opcode (0x00) if no .fillupper has been specified.