HD6417660 RENESAS [Renesas Technology Corp], HD6417660 Datasheet - Page 209

• Manufacturer Part Number: HD6417660
• Description: Renesas 32-Bit RISC Microcomputer
• Manufacturer: RENESAS [Renesas Technology Corp]

SPC Saved by an Exception in Repeat Control Period: If an exception is accepted in the repeat
control period while the repeat counter (RC[11:0]) in the SR register is two or greater, the program
counter to be saved may not indicate the value to be returned correctly. To execute the repeat
control after returning from an exception processing, the return address must indicate an
instruction prior to a repeat detection instruction. Accordingly, if an exception is accepted in
repeat control period, an exception other than re-execution type exception by a repeat detection
instruction cannot return to the repeat control correctly.
Table 4.3
Note:
Instruction Where an
Exception Occurs
RptDtct
RptDtct1
RptDtct2
RptDtct3
If a re-execution type exception is accepted at an instruction in the hatched areas above, a
return address to be saved in the SPC is incorrect. If SR.RC[11:0] is 1 or 0, a correct return
address is saved in the SPC.
The following symbols are used here.
RptDtct:
RptDtct1:
RptDtct2:
RptDtct3:
RS:
SPC Value when a Re-Execution Type Exception Occurs in Repeat Control
Repeat detection instruction address
An instruction address one instruction following the repeat detection
instruction (In a repeat loop consisting of one to three instructions, RptDtct1 is
equal to RptStart.)
An instruction address two instruction following the repeat detection
instruction
An instruction address three instruction following the repeat detection
instruction
Repeat start instruction address
1
RptDtct
RptDtct1


Number of Instructions in a Repeat Loop
2
RptDtct
RptDtct1
RptDtct1

3
RptDtct
RptDtct1
RptDtct1
RptDtct1
Rev. 1.00, 02/04, page 171 of 804
4 or Greater
RptDtct
RptDtct1
RS-4
RS-2