assembler version of calibrateoscillator - 1952 bytes

still needs cleaning up

1 files changed, 199 insertions, 1 deletions

diff --git a/firmware/usbdrv/usbdrvasm.S b/firmware/usbdrv/usbdrvasm.S
index b03b709..29c634a 100644
--- a/firmware/usbdrv/usbdrvasm.S
+++ b/firmware/usbdrv/usbdrvasm.S
@@ -282,7 +282,81 @@ usbCrc16Append:
 #undef scratch
 
 
-#if USB_CFG_HAVE_MEASURE_FRAME_LENGTH
+#if USB_CFG_HAVE_MEASURE_FRAME_LENGTHx
+#ifdef __IAR_SYSTEMS_ASM__
+/* Register assignments for usbMeasureFrameLength on IAR cc */
+/* Calling conventions on IAR:
+ * First parameter passed in r16/r17, second in r18/r19 and so on.
+ * Callee must preserve r4-r15, r24-r29 (r28/r29 is frame pointer)
+ * Result is passed in r16/r17
+ * In case of the "tiny" memory model, pointers are only 8 bit with no
+ * padding. We therefore pass argument 1 as "16 bit unsigned".
+ */
+#   define resL     r16
+#   define resH     r17
+#   define cnt16L   r30
+#   define cnt16H   r31
+#   define cntH     r18
+
+#else  /* __IAR_SYSTEMS_ASM__ */ 
+/* Register assignments for usbMeasureFrameLength on gcc */
+/* Calling conventions on gcc:
+ * First parameter passed in r24/r25, second in r22/23 and so on.
+ * Callee must preserve r1-r17, r28/r29
+ * Result is passed in r24/r25
+ */
+#   define resL     r24
+#   define resH     r25
+#   define cnt16L   r24
+#   define cnt16H   r25
+#   define cntH     r26
+#endif
+#   define cnt16    cnt16L
+
+; extern unsigned usbMeasurePacketLength(void);
+; returns time between two idle strobes in multiples of 7 CPU clocks
+.global usbMeasureFrameLength
+usbMeasureFrameLength:
+    ldi     cntH, 6         ; wait ~ 10 ms for D- == 0
+    clr     cnt16L
+    clr     cnt16H
+usbMFTime16:
+    dec     cntH
+    breq    usbMFTimeout
+usbMFWaitStrobe:            ; first wait for D- == 0 (idle strobe)
+    sbiw    cnt16, 1        ;[0] [6]
+    breq    usbMFTime16     ;[2]
+    sbic    USBIN, USBMINUS ;[3]
+    rjmp    usbMFWaitStrobe ;[4]
+usbMFWaitIdle:              ; then wait until idle again
+    sbis    USBIN, USBMINUS ;1 wait for D- == 1
+    rjmp    usbMFWaitIdle   ;2
+    ldi     cnt16L, 1       ;1 represents cycles so far
+    clr     cnt16H          ;1
+usbMFWaitLoop:
+    in      cntH, USBIN     ;[0] [7]
+    adiw    cnt16, 1        ;[1]
+    breq    usbMFTimeout    ;[3]
+    andi    cntH, USBMASK   ;[4]
+    brne    usbMFWaitLoop   ;[5]
+usbMFTimeout:
+#if resL != cnt16L
+    mov     resL, cnt16L
+    mov     resH, cnt16H
+#endif
+    ret
+
+#undef resL
+#undef resH
+#undef cnt16
+#undef cnt16L
+#undef cnt16H
+#undef cntH
+
+#endif  /* USB_CFG_HAVE_MEASURE_FRAME_LENGTH */
+
+
+#if USB_CFG_HAVE_MEASURE_FRAME_LENGTHx
 #ifdef __IAR_SYSTEMS_ASM__
 /* Register assignments for usbMeasureFrameLengthDecreasing on IAR cc */
 /* Calling conventions on IAR:
@@ -350,6 +424,130 @@ usbDFWaitLoop:
 
 #endif  /* USB_CFG_HAVE_MEASURE_FRAME_LENGTH */
 
+
+
+#if USB_CFG_HAVE_MEASURE_FRAME_LENGTH
+#ifdef __IAR_SYSTEMS_ASM__
+/* Register assignments for usbMeasureFrameLengthDecreasing on IAR cc */
+/* Calling conventions on IAR:
+ * First parameter passed in r16/r17, second in r18/r19 and so on.
+ * Callee must preserve r4-r15, r24-r29 (r28/r29 is frame pointer)
+ * Result is passed in r16/r17
+ * In case of the "tiny" memory model, pointers are only 8 bit with no
+ * padding. We therefore pass argument 1 as "16 bit unsigned".
+ */
+
+#   define resL     r16
+#   define resH     r17
+#   define cnt16L   r30
+#   define cnt16H   r31
+#   define cntH     r18
+
+#else  /* __IAR_SYSTEMS_ASM__ */ 
+/* Register assignments for usbMeasureFrameLength on gcc */
+/* Calling conventions on gcc:
+ * First parameter passed in r24/r25, second in r22/23 and so on.
+ * Callee must preserve r1-r17, r28/r29
+ * Result is passed in r24/r25
+ */
+
+#   define i		r20	
+#   define opV		r19
+#   define opD		r18
+#   define try		r27
+#   define stp		r26
+#   define cnt16L   r24
+#   define cnt16H   r25
+#endif
+#   define cnt16    cnt16L
+
+; extern void calibrateOscillatorASM(void);
+
+.global calibrateOscillatorASM
+calibrateOscillatorASM:
+
+	cli
+	ldi		i, 10		; 10 iterations
+
+	ldi		opD, 255	
+
+	ldi		try, 128	; calibration start value
+	ldi		stp, 64		; initial step width
+
+usbCOloop:
+
+	out		OSCCAL, try
+	nop
+
+	; Delay values = F_CPU * 999e-6 / 5 + 0.5
+	
+#if (F_CPU == 16500000)
+	ldi		cnt16L, lo8(3297)
+	ldi		cnt16H, hi8(3297)
+#define usbok
+#endif
+
+#if (F_CPU == 12800000)
+	ldi		cnt16L, lo8(2557)
+	ldi		cnt16H, hi8(2557)
+#define usbok
+#endif
+
+#ifndef usbok
+	#error "calibrateOscillatorASM: no delayvalues defined for this F_CPU setting"
+#endif
+#undef usbok
+
+usbCOWaitStrobe:            ; first wait for D- == 0 (idle strobe)
+    sbic    USBIN, USBMINUS ;
+    rjmp    usbCOWaitStrobe ;
+usbCOWaitIdle:              ; then wait until idle again
+    sbis    USBIN, USBMINUS ;1 wait for D- == 1
+    rjmp    usbCOWaitIdle   ;2
+usbCOWaitLoop:
+	sbiw	cnt16,1			;[0] [5]
+    sbic    USBIN, USBMINUS ;[2] 
+    rjmp    usbCOWaitLoop   ;[3]
+
+	sbrs	cnt16H, 7		;delay overflow?
+	rjmp	usbCOclocktoolow
+	sub		try, stp
+	neg		cnt16L
+	rjmp	usbCOclocktoohigh
+usbCOclocktoolow:
+	add		try, stp
+usbCOclocktoohigh:
+	lsr		stp
+	brne	usbCOstepnotzero
+	cp		opD, cnt16L
+	brcs	usbCOnoimprovement
+	in		opV, OSCCAL
+	mov		opD, cnt16L
+usbCOnoimprovement:
+	ldi		stp, 1
+usbCOstepnotzero:
+	subi	i, 1
+	brne	usbCOloop
+
+	out		OSCCAL, opV
+	nop
+	sei
+    ret
+
+#undef i
+#undef opV
+#undef opD
+#undef try
+#undef stp
+#undef cnt16
+#undef cnt16L
+#undef cnt16H
+
+
+#endif  /* USB_CFG_HAVE_MEASURE_FRAME_LENGTH */
+
+
+
 ;----------------------------------------------------------------------------
 ; Now include the clock rate specific code
 ;----------------------------------------------------------------------------