Texas Instruments TMS320C28x Reference Manual page 248

EDIS
SYNTAX OPTIONS
EDIS
Operands
Description
Flags and EALLOW
Modes
Repeat
Example
; Enable access to RegA and RegB which are EALLOW protected:
EALLOW
NOP
NOP
AND
MOV
EDIS
0111 0110 0001 1010
None
Disable access to emulation space and other protected registers.
This instruction clears the EALLOW bit in status register ST1. When this bit
is clear, the C28x CPU does not allow write access to the memory−mapped
emulation registers and other protected registers. See the data sheet for
your particular device to determine which registers the EALLOW bit
protects.
To allow write access to the registers, use the EALLOW instruction.
The EALLOW flag is cleared.
This instruction is not repeatable. If this instruction follows the RPT
instruction, it resets the repeat counter (RPTC) and executes only once.
; Enable access to selected registers
; Wait 2 cycles for enable to take
; effect. The number of cycles is device
; and/or register dependant.
@RegA,#0x4000 ; RegA = RegA AND 0x0400
@RegB,#0 ; RegB = 0
; Disable access to selected registers
Disable Write Access to Protected Registers
OPCODE OBJMODE
EDIS
RPT CYC
X − 4
6-91