Slot Inst | 6 3 | 6 2 | 6 1 | 6 0 | 5 9 | 5 8 | 5 7 | 5 6 | 5 5 | 5 4 | 5 3 | 5 2 | 5 1 | 5 0 | 4 9 | 4 8 | 4 7 | 4 6 | 4 5 | 4 4 | 4 3 | 4 2 | 4 1 | 4 0 | 3 9 | 3 8 | 3 7 | 3 6 | 3 5 | 3 4 | 3 3 | 3 2 | 3 1 | 3 0 | 2 9 | 2 8 | 2 7 | 2 6 | 2 5 | 2 4 | 2 3 | 2 2 | 2 1 | 2 0 | 1 9 | 1 8 | 1 7 | 1 6 | 1 5 | 1 4 | 1 3 | 1 2 | 1 1 | 1 0 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
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Format x24 - 24 bit(s) | 0 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
LDCT | 1 | 1 | 1 | 1 | 0 | 0 | 0 | 1 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | ||||||||||||||||||||||||||||||||||||||||||||||||
t | 3 | 2 | 1 | 0 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
s | 3 | 2 | 1 | 0 |
LDCT at, as
extern int XT_LDCT(const int * s);
(please consult the Xtensa ® Instruction Set Architecture Reference Manual for any cross references and additional information)
LDCT
is not part of the Xtensa Instruction Set Architecture, but is instead specific to an implementation. That is, it may not exist in all implementations of the Xtensa ISA and its exact method of addressing the cache may depend on the implementation.
LDCT
is intended for reading the RAM array that implements the data cache tags as part of manufacturing test.
LDCT
uses the contents of address register as
to select a line in the data cache, reads the tag associated with this line, and writes the result to address register at
. The value written to at
is described under Cache Tag Format in .
LDCT
is a privileged instruction.
if CRING != 0 then Exception (PrivilegedCause) else index ← AR[s]x-1..z-2 AR[t] ← DataCacheTag[index] // see Implementation Notes below endif