From: Jonathan Larmour <jlarmour@redhat.com>
To: Ling Su <lingsu@palmmicro.com>,
eCos discussion <ecos-discuss@sources.redhat.com>
Subject: Re: [ECOS] Regarding to eCos on VRC4373
Date: Wed, 10 Jan 2001 09:17:00 -0000 [thread overview]
Message-ID: <3A5C9902.4BE2B9F7@redhat.com> (raw)
In-Reply-To: <005e01c07ad5$5ba58210$0301a8c0@leopard>
Ling Su wrote:
>
> Another questions is: What's the time unit used in eCos, in kernel API or
> timer/counter object, such as cyg_thread_delay(time), how to set the delay
> time, it is in microsecond unit or more?
It is in clock ticks, which are platform-specific. You can use the kernel
API functions at
http://sources.redhat.com/ecos/docs-latest/ref/ecos-ref.9.html
Specifically, look at the definition of cyg_resolution_t, and notice you
can use cyg_clock_get_resolution( cyg_real_time_clock ) to get a
cyg_resolution_t for your real-time-clock.
A shortcut given that you know the platform is to look at the CDL for the
vrc4373 which includes the fields CYGNUM_HAL_RTC_NUMERATOR and
CYGNUM_HAL_RTC_DENOMINATOR which correspond to the fields in the
cyg_resolution_t. This is 1000000000 and 100 respectively, giving
10,000,000 ns/tick == 10 ms/tick.
Jifl
--
Red Hat, Rustat House, Clifton Road, Cambridge, UK. Tel: +44 (1223) 271062
Un cheval, pas du glue. Pas du cheval, beaucoup du glue. || Opinions==mine
next prev parent reply other threads:[~2001-01-10 9:17 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-01-09 14:59 Ling Su
2001-01-09 16:44 ` Jonathan Larmour
2001-01-09 23:37 ` Ling Su
2001-01-10 3:30 ` Nick Garnett
2001-01-10 5:15 ` [ECOS] assertion checks for stack Joerg Rapka
2001-01-10 9:10 ` [ECOS] Regarding to eCos on VRC4373 Jonathan Larmour
2001-01-10 0:19 ` Ling Su
2001-01-10 9:08 ` Jonathan Larmour
[not found] ` <005e01c07ad5$5ba58210$0301a8c0@leopard>
2001-01-10 9:17 ` Jonathan Larmour [this message]
2001-01-10 14:08 ` Ling Su
2001-01-10 14:17 ` Jonathan Larmour
2001-01-10 15:45 ` Grant Edwards
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