diff -r 000000000000 -r 5de814552237 navienginebsp/naviengine_assp/variant_timestamp.h --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/navienginebsp/naviengine_assp/variant_timestamp.h Tue Sep 28 18:00:05 2010 +0100 @@ -0,0 +1,69 @@ +/* +* Copyright (c) 2008-2009 Nokia Corporation and/or its subsidiary(-ies). +* All rights reserved. +* This component and the accompanying materials are made available +* under the terms of "Eclipse Public License v1.0" +* which accompanies this distribution, and is available +* at the URL "http://www.eclipse.org/legal/epl-v10.html". +* +* Initial Contributors: +* Nokia Corporation - initial contribution. +* +* Contributors: +* +* Description: +* The frequency of the system timestamp counter in Hz +* The timestamp counter is a 64 bit value which is required to increment at a +* constant rate of at least 1MHz and not to wrap in any reasonable amount of time. +* +*/ + + + + + +const TUint32 KTimestampFrequency = 66666667u; + +#ifdef __DEFINE_NKERN_TIMESTAMP_ASM__ +/* If NKern::Timestamp() is written in assembler define it here +*/ + +EXPORT_C __NAKED__ TUint64 NKern::Timestamp() + { + // Return a 64 bit high resolution timestamp count + // Timer 1 counts from 00000000 to FFFFFEFF and then wraps back to 0 + // Timer 2 counts from 00000000 to FFFFFFFF and then wraps back to 0 + // Both timers increment at 66.667MHz (15ns period) + // Algorithm: + // volatile TUint32 t2 = Timer2Count; // must read t2 first + // volatile TUint32 t1 = Timer1Count; + // TUint32 n = (t1-t2)>>8; // number of times T1 has wrapped + // return t1 + n * 0xFFFFFF00; + + asm("ldr r3, 1f "); // r3 = address of T1 counter + asm("mrs r12, cpsr "); + __ASM_CLI(); // interrupts off + asm("ldr r1, [r3, #0x400] "); // r1 = t2 + asm("ldr r0, [r3] "); // r0 = t1 + asm("msr cpsr, r12 "); // restore interrupts + asm("sub r1, r0, r1 "); // t1-t2 + asm("mov r1, r1, lsr #8 "); // n = (t1-t2)>>8, now have r1:r0 = 2^32*n + t1 + asm("subs r0, r0, r1, lsl #8 "); // subtract 256*n + asm("sbcs r1, r1, #0 "); // propagate borrow + __JUMP(,lr); + + asm("1: "); +#ifdef __MEMMODEL_DIRECT__ + asm(".word 0x18036400 "); // address of timer 1 counter +#else + asm(".word 0xC6003400 "); // address of timer 1 counter +#endif + } + +#endif + +#ifdef __DEFINE_NKERN_TIMESTAMP_CPP__ +/* If NKern::Timestamp() is written in C++ define it here +*/ +#endif +