# ==================================================================== # # counters.cdl # # configuration data related to the kernel counters and clocks # # ==================================================================== ## ####ECOSGPLCOPYRIGHTBEGIN#### ## ------------------------------------------- ## This file is part of eCos, the Embedded Configurable Operating System. ## Copyright (C) 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc. ## ## eCos is free software; you can redistribute it and/or modify it under ## the terms of the GNU General Public License as published by the Free ## Software Foundation; either version 2 or (at your option) any later ## version. ## ## eCos is distributed in the hope that it will be useful, but WITHOUT ## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or ## FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License ## for more details. ## ## You should have received a copy of the GNU General Public License ## along with eCos; if not, write to the Free Software Foundation, Inc., ## 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. ## ## As a special exception, if other files instantiate templates or use ## macros or inline functions from this file, or you compile this file ## and link it with other works to produce a work based on this file, ## this file does not by itself cause the resulting work to be covered by ## the GNU General Public License. However the source code for this file ## must still be made available in accordance with section (3) of the GNU ## General Public License v2. ## ## This exception does not invalidate any other reasons why a work based ## on this file might be covered by the GNU General Public License. ## ------------------------------------------- ## ####ECOSGPLCOPYRIGHTEND#### # ==================================================================== ######DESCRIPTIONBEGIN#### # # Author(s): jskov # Original data: nickg # Contributors: # Date: 1999-07-05 # #####DESCRIPTIONEND#### # # ==================================================================== cdl_option CYGVAR_KERNEL_COUNTERS_CLOCK { display "Provide real-time clock" requires CYGIMP_KERNEL_INTERRUPTS_DSRS default_value 1 description " On all current target systems the kernel can provide a real-time clock. This clock serves two purposes. First it is necessary to support clock and alarm related functions. Second it is needed to implement timeslicing in some of the schedulers including the mlqueue scheduler. If the application does not require any of these facilities then it is possible to disable the real time clock support completely." } cdl_option CYGNUM_KERNEL_COUNTERS_CLOCK_ISR_PRIORITY { display "Interrupt priority for the real-time clock" active_if CYGVAR_KERNEL_COUNTERS_CLOCK flavor data default_value { is_loaded(CYGNUM_HAL_KERNEL_COUNTERS_CLOCK_ISR_DEFAULT_PRIORITY) ? CYGNUM_HAL_KERNEL_COUNTERS_CLOCK_ISR_DEFAULT_PRIORITY : 1 } description " The implementation of the kernel's real-time clock typically involves installing an interrupt handler on a suitable hardware timer. This option controls the priority level used for that interrupt. On most platforms the value is not important because the clock ISR leaves most of the work to be done by the DSR. However some processors have interrupt controllers with special requirements for the interrupt priorities, in which case application developers must be able to manipulate the clock's priority." } cdl_interface CYGINT_KERNEL_COUNTERS { requires 1 == CYGINT_KERNEL_COUNTERS no_define } # NOTE: these option should really be a single enum. cdl_option CYGIMP_KERNEL_COUNTERS_SINGLE_LIST { display "Implement counters using a single list" default_value 1 implements CYGINT_KERNEL_COUNTERS description " There are two different implementations of the counter objects. The first implementation stores all alarms in a single linked list. The alternative implementation uses a table of linked lists. A single list is more efficient in terms of memory usage and is generally adequate when the application only makes use of a small number of alarms." } cdl_component CYGIMP_KERNEL_COUNTERS_MULTI_LIST { display "Implement counters using a table of lists" default_value 0 implements CYGINT_KERNEL_COUNTERS description " There are two different implementations of the counter objects. The first implementation stores all alarms in a single linked list. The alternative implementation uses a table of linked lists, with the size of the table being a separate configurable option. For more complicated operations it is better to have a table of lists since this reduces the amount of computation whenever the timer goes off. Assuming a table size of 8 (the default value) on average the timer code will only need to check 1/8 of the pending alarms instead of all of them." cdl_option CYGNUM_KERNEL_COUNTERS_MULTI_LIST_SIZE { display "Size of counter list table" flavor data legal_values 1 to 1024 default_value 8 description " If counters are implemented using an array of linked lists then this option controls the size of the array. A larger size reduces the amount of computation that needs to take place whenever the timer goes off, but requires extra memory." } } cdl_option CYGIMP_KERNEL_COUNTERS_SORT_LIST { display "Sort the counter list" default_value 0 description " Sorting the counter lists reduces the amount of work that has to be done when a counter tick is processed, since the next alarm to expire is always at the front of the list. However, it makes adding an alarm to the list more expensive since a search must be done for the correct place to put it. Many alarms are used to implement timeouts, which seldom trigger, so it is worthwhile optimizing this case. For this reason sorted list are disabled by default." } cdl_option CYGVAR_KERNEL_COUNTERS_CLOCK_LATENCY { display "Measure real-time \[clock\] interrupt latency" requires CYGVAR_KERNEL_COUNTERS_CLOCK default_value 0 description " Measure the interrupt latency as seen by the real-time clock timer interrupt. This requires hardware support, defined by the HAL_CLOCK_LATENCY() macro." } cdl_option CYGVAR_KERNEL_COUNTERS_CLOCK_DSR_LATENCY { display "Measure real-time \[clock\] DSR latency" requires CYGVAR_KERNEL_COUNTERS_CLOCK_LATENCY default_value CYGVAR_KERNEL_COUNTERS_CLOCK_LATENCY description " Measure the DSR latency as seen by the real-time clock timer interrupt. This requires hardware support, defined by the HAL_CLOCK_LATENCY() macro." } cdl_option CYGNUM_KERNEL_COUNTERS_RTC_RESOLUTION { display "RTC resolution" flavor data calculated {"{CYGNUM_HAL_RTC_NUMERATOR, CYGNUM_HAL_RTC_DENOMINATOR}"} description " This option automatically defines the tuple which is used to initialize the RTC resolution, consisting of a numerator and denominator. The values of the numerator and denominator are defined by the HAL." } cdl_option CYGNUM_KERNEL_COUNTERS_RTC_PERIOD { display "RTC period" flavor data calculated {"CYGNUM_HAL_RTC_PERIOD"} description " This option defines the RTC period to be used in setting the system clock hardware. It is essentially an alias for CYGNUM_HAL_RTC_PERIOD, which is defined in the HAL." } # EOF counters.cdl