ST20-C1 STMICROELECTRONICS [STMicroelectronics], ST20-C1 Datasheet - Page 170

• Manufacturer Part Number: ST20-C1
• Description: Instruction Set Reference Manual
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

A.1
A.2
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mac_count
mac_buffer
mac_scale
mac_mode
global_interrupt_disable
local_interrupt_disable
overflo w
underflo w
carry
user_mode
interrupt_mode
trap_mode
sleep
reserved
start_next_task
timeslice_enable
timeslice_count
Exception level
0 - 255
Status Register
Full name
Exception levels
-1
-2
-3
-4
-5
-6
-7
User exception
el_breakpoint_trap
el_illegal_instr_trap
el_idle_trap
el_schedule_exception_trap
el_run_trap
el_stop_trap
el_timeslice_trap
Table A.1 Status register bits (see section 3.3.2)
Table A.2 Exception levels (see Chapter 6)
Bit numbers
Name
11 - 12
26 - 31
8 - 10
0 - 7
13
14
15
16
17
18
19
20
21
22
23
24
25
Multiply-accumulate number of steps.
Multiply-accumulate data buffer size code.
Multiply-accumulate scaling code.
Multiply-accumulate accumulator format code.
Disable external interrupts until explicitly enabled.
Disable external interrupts until process descheduled.
An arithmetic operation gave a positive overflow.
An arithmetic operation gave a negative overflow.
An arithmetic operation produced a carry.
A user process is executing.
An interrupt handler is executing.
A trap handler is executing.
The processor is due to go to sleep.
Reserved.
The CPU must start executing a new process.
Timeslicing is enabled.
Timeslice clock.
Meaning when set or meaning of value
User exception levels.
Breakpoint trap.
Illegal op-code trap.
CPU idle trap.
Schedule user process as exception trap.
Run process trap.
Stop process trap.
Timeslice trap.
Description