XCALL pma,COND
6-376
XCALL pma,COND C2xLP Source-Compatible Function Call
SYNTAX OPTIONS OPCODE OBJMODE RPT CYC
XCALL pma,COND 0101 0110 1110 COND
CCCC CCCC CCCC CCCC
1 − 7/4
Operands pma 16-bit immediate program-memory address,
can only access high 64K of program space range (0x3F0000 to 0x3FFFFF)
COND Conditional codes:
COND Syntax Description Flags Tested
0000 NEQ Not Equal To Z = 0
0001 EQ Equal To Z = 1
0010 GT Greater Then Z = 0 AND N = 0
0011 GEQ Greater Then Or Equal
To
N = 0
0100 LT Less Then N = 1
0101 LEQ Less Then Or Equal To Z = 1 OR N = 1
0110 HI Higher C = 1 AND Z = 0
0111 HIS, C Higher Or Same, Carry
Set
C = 1
1000 LO, NC Lower, Carry Clear C = 0
1001 LOS Lower Or Same C = 0 OR Z = 1
1010 NOV No Overflow V = 0
1011 OV Overflow V = 1
1100 NTC Test Bit Not Set TC = 0
1101 TC Test Bit Set TC = 1
1110 NBIO BIO Input Equal To
Zero
BIO = 0
1111 UNC Unconditional −
Description Conditional call. If the specified condition is true, then the low 16 bits of the
return address is pushed onto the software stack and the low 16 bits of the
PC are loaded with the 16-bit immediate ”pma” value and the upper 6 bits of
the PC are forced to 0x3F; otherwise continue execution with instruction
following the XCALL operation:
if(COND = true)
{
temp(21:0) = PC + 2;
[SP] = temp(15:0);
SP = SP + 1;
PC = 0x3F:pma;
}
else
PC = PC + 2;
Note: This instruction can only transfer program control to a location located in the upper 64K
range of program space (0x3F0000 to 0x3FFFFF). To return from a call made by
XCALL, the XRETC instruction must be used. The cycle times for this operation are:
If (COND = true) then the instruction takes 7 cycles.
If (COND = false) then the instruction takes 4 cycles.
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