;*************************************************************** ;* Macro LONGC ;Long Call ;by Walter Quitt ;*************************************************************** LONGC MACRO SUBROUTINE bsf CPUSTA,GLINTD ;interrupts off movlw HIGH (SUBROUTINE) movfp WREG,PCLATH ;Z unaffected bcf CPUSTA,GLINTD ;interrupts on lcall LOW (SUBROUTINE) ENDM
Olin Lathrop [olin at cognivis.com] of cognivis (978) 772-3129 says
; ;******************** ; ; Macro SKIP_WLE ; ; Skip the next instruction if W was less than or equal to the value ; it was subtracted from. This assumes that the carry flag has been ; preserved from the last SUBWF or SUBLW instruction. ; skip_wle macro if fam_17 btfss alusta, c exitm endif btfss status, c ;skip if no borrow occurred endm ; ;******************** ; ; Macro SKIP_WGT ; ; Skip the next instruction if W was greater than the value ; it was subtracted from. This assumes that the carry flag has been ; preserved from the last SUBWF or SUBLW instruction. ; skip_wgt macro if fam_17 btfsc alusta, c exitm endif btfsc status, c ;skip if a borrow occurred endm ; ;******************** ; ; Macro SKIP_Z ; ; Skip the next instruction if the zero flag is set. ; skip_z macro if fam_17 btfss alusta, z exitm endif btfss status, z endm ; ;******************** ; ; Macro SKIP_NZ ; ; Skip the next instruction if the zero flag is not set. ; skip_nz macro if fam_17 btfsc alusta, z exitm endif btfsc status, z endm ; ;******************** ; ; Macro SKIP_CARR ; ; Skip the next instruction if a carry occurred. ; skip_carr macro if fam_17 btfss alusta, c exitm endif btfss status, c endm ; ;******************** ; ; Macro SKIP_NCARR ; ; Skip the next instruction if no carry occurred. ; skip_ncarr macro if fam_17 btfsc alusta, c exitm endif btfsc status, c endm ; ;******************** ; ; Macro SKIP_BORR ; ; Skip the next instruction if a borrow occurred. ; skip_borr macro if fam_17 btfsc alusta, c exitm endif btfsc status, c endm ; ;******************** ; ; Macro SKIP_NBORR ; ; Skip the next instruction if no borrow occurred. ; skip_nborr macro if fam_17 btfss alusta, c exitm endif btfss status, c endm ; ;******************** ; ; Macro INTR_OFF ; ; Globally disable interrupts without changing which interrupts are ; individually disabled. This macro together with INTR_ON can be used ; around small sections of code that need to run with interrupts off. ; intr_off macro if fam_16 bcf intcon, gie endif if fam_17 bsf cpusta, glintd endif endm ; ;******************** ; ; Macro INTR_ON ; ; Globally enable interrupts without changing which interrupts are ; individually enabled. This macro together with INTR_OFF can be used ; around small sections of code that need to run with interrupts off. ; intr_on macro if fam_16 bsf intcon, gie endif if fam_17 bcf cpusta, glintd endif endm
Simon says:
BETTER?: intr_off macro if fam_16 foo: bcf intcon, gie btfsc intcon, gie goto foo endif if fam_17 bar: bsf cpusta, glintd btfss cpusta, glintd goto bar endif endm cut & paste of the reasoning behind the code from Thomas' code: ;If an IRQ happens when the "bcf intcon,gie" line is executing, ;the GIE bit will be cleared, but the interrupt will still occur. ;If the interrupt routine has a RETFIE instruction at the ;end, (which is the usual state of affairs),then GIE will ;be set to 1 again.
Questions:
What does the LONGC macro do ? Why would anyone ever want to use it ? I'm missing the point."
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