; setup a sleep function.

/************************************************************
* Interrupt Vectors (offset from 0xFFE0)

#define PORT1_VECTOR        (2 * 2u)  0xFFE4 Port 1 
#define PORT2_VECTOR        (3 * 2u)  0xFFE6 Port 2 
#define ADC10_VECTOR        (5 * 2u)  0xFFEA ADC10 
#define USCIAB0TX_VECTOR    (6 * 2u)  0xFFEC USCI A0/B0 Transmit 
#define USCIAB0RX_VECTOR    (7 * 2u)  0xFFEE USCI A0/B0 Receive 
#define TIMER0_A1_VECTOR    (8 * 2u)  0xFFF0 Timer0)A CC1, TA0 
#define TIMER0_A0_VECTOR    (9 * 2u)  0xFFF2 Timer0_A CC0 
#define WDT_VECTOR          (10 * 2u) 0xFFF4 Watchdog Timer 
#define COMPARATORA_VECTOR  (11 * 2u) 0xFFF6 Comparator A 
#define TIMER1_A1_VECTOR    (12 * 2u) 0xFFF8 Timer1_A CC1-4, TA1 
#define TIMER1_A0_VECTOR    (13 * 2u) 0xFFFA Timer1_A CC0 
#define NMI_VECTOR          (14 * 2u) 0xFFFC Non-maskable 
#define RESET_VECTOR        (15 * 2u) 0xFFFE Reset [Highest Priority] 

services:
- UCA0 interupt enable.
- Activate LPM4 mode. 
- UCA0 ISR disables lpm4 mode.
- UCA0 interupt disable.

***************************************************************/

;C IRXON    --             turn UCA0 interrupt on
    HEADER IRXON,5,'IRXON',DOCODE
       BIS.B #UCA0RXIE,IE2
       NEXT

;C IRXOFF    --             turn UCA0 interrupt off
    HEADER IRXOFF,6,'IRXOFF',DOCODE
       BIC.B #UCA0RXIE,IE2
       NEXT

;C LPM_WAKE    -- adr        LPM wake up interrupt service routine address
;  turns off LPM mode.
    HEADER LPM_WAKE,8,'LPM_WAKE',DOCON
       DW lpm_wake
lpm_wake:
        ; BIS.B #BIT0,&021h      ; red LED on
        BIC #(GIE+LPM4),0(RSP) ; clear SR on return stack - turn CPU on.        
        RETI

;Z LPM4      --           ; Enter low power mode 4, wake on interrupt.
     HEADER setlpm4,4,'LPM4',DOCODE
         ; BIC.B #BIT0,&021h    ; red LED off
         PUSH SR
         BIS #(GIE+LPM4),SR   ; CPU stops here
         POP SR
         ; DINT
         ; BIS.B #BIT0,&021h    ; red LED on
         NEXT

;Z LPM0      --           ; Enter low power mode 0, wake on interrupt.
     HEADER setlpm0,4,'LPM0',DOCODE
         ; BIC.B #BIT0,&021h    ; red LED off
         PUSH SR
         BIS #(GIE+LPM0),SR   ; CPU stops here
         POP SR
         ; DINT
         ; BIS.B #BIT0,&021h    ; red LED on
         NEXT

;Z SETIRX  --            set IRX vector to wakr up MCU  
;    lpm_wake-isr_rx FFEE interrrupt ;
     HEADER SETIRX,6,'SETIRX',DOCOLON
         DW LPM_WAKE,lit,(intvecs+USCIAB0RX_VECTOR),INTERRUPT
         DW EXIT
         

/**************************************************************
;Z IE2    --  adr     Interrupt enable register for UCA0
     HEADER IE2CON,3,'IE2',DOCON
         DW IE2
         
;Z UCA0RXIE    -- adr      Interrupt mask UCA0
     HEADER UCA0RXIEmask,8,'UCA0RXIE',DOCON
         DW UCA0RXIE
***************************************************************/

; finis