ARM Architecture Reference Manual ARMv7-A and ARMv7-R edition

ThumbEE Handler Base Register (TEEHBR)
Application Level Programmers’ Model
The ThumbEE Handler Base Register (TEEHBR) holds the base address for ThumbEE handlers.
The TEEHBR is:
a CP14 register
a 32-bit read/write register, with access rights that depend on the current privilege and the value of
the TEECR.XED bit:
— privileged accesses are always permitted
— when TEECR.XED == 0, unprivileged accesses are permitted
— when TEECR.XED == 1, the result of an unprivileged access is UNDEFINED.
when the Security Extensions are implemented, a Common register.
The format of the TEEHBR is:
31 2 1 0
HandlerBase SBZ
HandlerBase, bits [31:2]
The address of the ThumbEE Handler_00 implementation. This is the address of the first of
the ThumbEE handlers.
The reset value of this field is UNKNOWN.
bits [1:0] Reserved, SBZ.
The effects of a write to this register on ThumbEE handler entry are only guaranteed to be visible to
subsequent instructions after the execution of an ISB instruction, an exception entry or an exception return.
However, a read of this register always returns the value most recently written to the register.
To access the TEEHBR, read or write the CP14 registers with an MRC or MCR instruction with set to 6,
set to c1, set to c0, and set to 0. For example:
MRC p14, 6, , c1, c0, 0 ; Read ThumbEE Handler Base Register
MCR p14, 6, , c1, c0, 0 ; Write ThumbEE Handler Base Register
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