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Integrating z80

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git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@463 42af7a65-404d-4744-a932-0658087f49c3
This commit is contained in:
patacongo 2007-12-30 18:13:22 +00:00
parent 1afeed4d05
commit 9a7e634a96
4 changed files with 24 additions and 7 deletions
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2
arch/z80/include/z80/irq.h
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@ -51,7 +51,7 @@
/* Z80 Interrupts */
#define Z80_IRQ_SYSTIMER (1)
#define Z80_IRQ_SYSTIMER (0)
#define NR_IRQS (1)
/* IRQ Stack Frame Format

13
arch/z80/src/common/up_head.asm
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@ -111,15 +111,22 @@ forever:
push af ; Offset 0: I with interrupt state in carry
di
; Call the interrupt decode logic. SP points to the beggining of the reg structure
; Call the interrupt decode logic. SP points to the beggining of the reg structure
ld hl, #0 ; Argument is the beginning of the reg structure
add hl, sp ;
push hl ;
push hl ; Place argument at the top of thest
call _up_decodeirq ; Decode the IRQ
; On return, HL points to the beginning of the reg structure to restore
; Note that (1) the argument pushed on the stack is not popped, and (2) the
; original stack pointer is lost. In the normal case (no context switch),
; HL will contain the value of the SP before the argument was pushed.
ld sp, hl ; Use the new stack pointer
; Restore registers. HL points to the beginning of the reg structure to restore
ld sp, hl ; Use the temp stack pointer
ex af, af' ; Select alternate AF
pop af ; Offset 0: AF' = I with interrupt state in carry
pop bc ; Offset 1: BC

7
arch/z80/src/common/up_irq.c
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@ -92,13 +92,14 @@ irqstate_t irqsave(void) __naked
void irqrestore(irqstate_t flags) __naked
{
_asm
di ; Assume disabled
pop hl ; HL = return address
pop af ; AF Carry bit hold interrupt state
jr nc, statedisable
ei
ret
statedisable:
di
ret
push af ; Restore stack
push hl ;
ret ; and return
_endasm;
}

9
arch/z80/src/z80/chip.h
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@ -45,6 +45,15 @@
* Definitions
************************************************************************************/
/* Bits in the Z80 FLAGS register */
#define Z80_C_FLAG 0x01 /* Bit 0: Carry flag */
#define Z80_N_FLAG 0x02 /* Bit 1: Add/Subtract flag */
#define Z80_PV_FLAG 0x04 /* Bit 2: Parity/Overflow flag */
#define Z80_H_FLAG 0x10 /* Bit 4: Half carry flag */
#define Z80_Z_FLAG 0x40 /* Bit 5: Zero flag */
#define Z80_S_FLAG 0x80 /* Bit 7: Sign flag */
/************************************************************************************
* Public Function Prototypes
************************************************************************************/