[ac7d5ef0] | 1 | /* Clock_init() |
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| 2 | * |
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| 3 | * |
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| 4 | * This is modified by Doug McBride to get it to work for the MC68EC040 |
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| 5 | * IDP board. The below comments are kept to show that some prior work |
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| 6 | * was done in the area and the modifications performed was application |
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| 7 | * specific for the IDP board to port it to. |
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| 8 | * |
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| 9 | * This routine initializes the mc68230 on the MC68EC040 board. |
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| 10 | * The tick frequency is 40 milliseconds. |
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| 11 | * |
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| 12 | * Input parameters: NONE |
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| 13 | * |
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| 14 | * Output parameters: NONE |
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| 15 | * |
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[08311cc3] | 16 | * COPYRIGHT (c) 1989-1999. |
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[ac7d5ef0] | 17 | * On-Line Applications Research Corporation (OAR). |
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| 18 | * |
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[98e4ebf5] | 19 | * The license and distribution terms for this file may be |
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| 20 | * found in the file LICENSE in this distribution or at |
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[03f2154e] | 21 | * http://www.OARcorp.com/rtems/license.html. |
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[ac7d5ef0] | 22 | * |
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| 23 | * $Id$ |
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| 24 | */ |
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| 25 | |
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| 26 | #include <stdlib.h> |
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| 27 | |
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[88d594a] | 28 | #include <bsp.h> |
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[3a4ae6c] | 29 | #include <rtems/libio.h> |
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[ac7d5ef0] | 30 | |
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| 31 | rtems_unsigned32 Clock_isrs; /* ISRs until next tick */ |
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| 32 | volatile rtems_unsigned32 Clock_driver_ticks; |
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| 33 | /* ticks since initialization */ |
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| 34 | rtems_isr_entry Old_ticker; |
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| 35 | |
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| 36 | extern rtems_configuration_table Configuration; |
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| 37 | extern void led_putnum(); |
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| 38 | void Disable_clock(); |
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| 39 | |
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[3a4ae6c] | 40 | #define CLOCK_VECTOR 0x4D |
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[ac7d5ef0] | 41 | |
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[3a4ae6c] | 42 | void Clock_exit( void ); |
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| 43 | |
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| 44 | /* |
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| 45 | * These are set by clock driver during its init |
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| 46 | */ |
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| 47 | |
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| 48 | rtems_device_major_number rtems_clock_major = ~0; |
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| 49 | rtems_device_minor_number rtems_clock_minor; |
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| 50 | |
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[ac7d5ef0] | 51 | |
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[3a4ae6c] | 52 | /* |
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| 53 | * ISR Handler |
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| 54 | * |
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| 55 | * |
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| 56 | * ((1ms * 6.5 MHz) / 2^5) = 203.125) where 6.5 MHz is the clock rate of the |
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| 57 | * MC68230, 2^5 is the prescaler factor, and 1ms is the common interrupt |
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| 58 | * interval for the Clock_isr routine. |
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| 59 | * Therefore, 203 (decimal) is the number to program into the CPRH-L registers |
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| 60 | * of the MC68230 for countdown. However, I have found that 193 instead of |
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| 61 | * 203 provides greater accuracy -- why? The crystal should be more accurate |
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| 62 | * than that |
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| 63 | */ |
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[ac7d5ef0] | 64 | |
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[3a4ae6c] | 65 | rtems_isr Clock_isr( |
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| 66 | rtems_vector_number vector |
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| 67 | ) |
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| 68 | { |
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| 69 | Clock_driver_ticks += 1; |
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| 70 | /* acknowledge interrupt |
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| 71 | TSR = 1; */ |
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| 72 | MC68230_WRITE (TSR, 1); |
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| 73 | |
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| 74 | if ( Clock_isrs == 1 ) { |
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| 75 | rtems_clock_tick(); |
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| 76 | /* Cast to an integer so that 68EC040 IDP which doesn't have an FPU doesn't |
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| 77 | have a heart attack -- if you use newlib1.6 or greater and get |
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| 78 | libgcc.a for gcc with software floating point support, this is not |
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| 79 | a problem */ |
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| 80 | Clock_isrs = |
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| 81 | (int)(BSP_Configuration.microseconds_per_tick / 1000); |
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| 82 | } |
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| 83 | else |
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| 84 | Clock_isrs -= 1; |
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[ac7d5ef0] | 85 | } |
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| 86 | |
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| 87 | void Disable_clock() |
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| 88 | { |
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| 89 | /* Disable timer */ |
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| 90 | MC68230_WRITE (TCR, 0x00); |
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| 91 | } |
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| 92 | |
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| 93 | void Install_clock( clock_isr ) |
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| 94 | rtems_isr_entry clock_isr; |
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| 95 | { |
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| 96 | Clock_driver_ticks = 0; |
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| 97 | Clock_isrs = (int)(Configuration.microseconds_per_tick / 1000); |
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| 98 | |
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| 99 | /* led_putnum('c'); * for debugging purposes */ |
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[3a4ae6c] | 100 | Old_ticker = (rtems_isr_entry) set_vector( clock_isr, CLOCK_VECTOR, 1 ); |
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[ac7d5ef0] | 101 | |
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[0dd1d44] | 102 | /* Disable timer for initialization */ |
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| 103 | MC68230_WRITE (TCR, 0x00); |
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| 104 | |
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| 105 | /* some PI/T initialization stuff here -- see comment in the ckisr.c |
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| 106 | file in this directory to understand why I use the values that I do */ |
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| 107 | /* Set up the interrupt vector on the MC68230 chip: |
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| 108 | TIVR = CLOCK_VECTOR; */ |
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| 109 | MC68230_WRITE (TIVR, CLOCK_VECTOR); |
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| 110 | |
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| 111 | /* Set CPRH through CPRL to 193 (not 203) decimal for countdown--see ckisr.c |
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| 112 | CPRH = 0x00; |
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| 113 | CPRM = 0x00; |
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| 114 | CPRL = 0xC1; */ |
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| 115 | MC68230_WRITE (CPRH, 0x00); |
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| 116 | MC68230_WRITE (CPRM, 0x00); |
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| 117 | MC68230_WRITE (CPRL, 0xC1); |
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| 118 | |
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| 119 | /* Enable timer and use it as an external periodic interrupt generator |
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| 120 | TCR = 0xA1; */ |
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[ac7d5ef0] | 121 | /* led_putnum('a'); * for debugging purposes */ |
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[0dd1d44] | 122 | MC68230_WRITE (TCR, 0xA1); |
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[ac7d5ef0] | 123 | |
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[0dd1d44] | 124 | /* |
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| 125 | * Schedule the clock cleanup routine to execute if the application exits. |
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| 126 | */ |
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| 127 | atexit( Clock_exit ); |
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[ac7d5ef0] | 128 | } |
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| 129 | |
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[3a4ae6c] | 130 | /* The following was added for debugging purposes */ |
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[ac7d5ef0] | 131 | void Clock_exit( void ) |
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| 132 | { |
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| 133 | rtems_unsigned8 data; |
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| 134 | |
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[0dd1d44] | 135 | /* disable timer |
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| 136 | data = TCR; |
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| 137 | TCR = (data & 0xFE); */ |
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| 138 | MC68230_READ (TCR, data); |
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| 139 | MC68230_WRITE (TCR, (data & 0xFE)); |
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[ac7d5ef0] | 140 | |
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[0dd1d44] | 141 | /* do not restore old vector */ |
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[ac7d5ef0] | 142 | } |
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[3a4ae6c] | 143 | |
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| 144 | rtems_device_driver Clock_initialize( |
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| 145 | rtems_device_major_number major, |
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| 146 | rtems_device_minor_number minor, |
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| 147 | void *pargp |
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| 148 | ) |
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| 149 | { |
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| 150 | Install_clock( Clock_isr ); |
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| 151 | |
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| 152 | /* |
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| 153 | * make major/minor avail to others such as shared memory driver |
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| 154 | */ |
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| 155 | |
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| 156 | rtems_clock_major = major; |
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| 157 | rtems_clock_minor = minor; |
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| 158 | |
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| 159 | return RTEMS_SUCCESSFUL; |
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| 160 | } |
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| 161 | |
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| 162 | rtems_device_driver Clock_control( |
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| 163 | rtems_device_major_number major, |
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| 164 | rtems_device_minor_number minor, |
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| 165 | void *pargp |
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| 166 | ) |
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| 167 | { |
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[9700578] | 168 | rtems_unsigned32 isrlevel; |
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[3a4ae6c] | 169 | rtems_libio_ioctl_args_t *args = pargp; |
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| 170 | |
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| 171 | if (args == 0) |
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| 172 | goto done; |
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| 173 | |
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| 174 | /* |
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| 175 | * This is hokey, but until we get a defined interface |
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| 176 | * to do this, it will just be this simple... |
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| 177 | */ |
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| 178 | |
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| 179 | if (args->command == rtems_build_name('I', 'S', 'R', ' ')) |
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| 180 | { |
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| 181 | Clock_isr(CLOCK_VECTOR); |
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| 182 | } |
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| 183 | else if (args->command == rtems_build_name('N', 'E', 'W', ' ')) |
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| 184 | { |
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[9700578] | 185 | rtems_interrupt_disable( isrlevel ); |
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| 186 | (void) set_vector( args->buffer, CLOCK_VECTOR, 1 ); |
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| 187 | rtems_interrupt_enable( isrlevel ); |
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[3a4ae6c] | 188 | } |
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| 189 | |
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| 190 | done: |
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| 191 | return RTEMS_SUCCESSFUL; |
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| 192 | } |
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| 193 | |
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