Chapter 5 Detailed Applications
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5.3 The Use of INT Instruction
MR308 has INT instruction interrupt numbers reserved for issuing service calls as listed in Table 5.2. For this
reason, when using software interrupts in a user application, do not use interrupt numbers 63 through 55 and be
sure to use some other numbers.
Table 5.2 Interrupt Number Assignment
Interrupt No. Service calls Used
63 Service calls that can be issued from only task context
62 Service calls that can be issued from only non-task context.
Service calls that can be issued from both task context and non-task context.
61 ret_int service call
60 dis_dsp service call
59 loc_cpu, iloc_cpu service call
58 ext_tsk service call
55 tsnd_dtq, twai_flg, vtsnd_dtq service call
5.4 The Use of registers of bank
The registers of bank is 0, when a task starts on MR308.
MR308 does not change the registers of bank in processing kernel.
You must pay attention to the followings.
Don’t change the regisers of bank in processing a task. If an interrupt handler with regisers of bank 1 have multiple interrupts of an interrupt handler with regis-
ers of bank 1 , the program can not execute normally.