Multiply-Accumulate Register (Mac); Initial Register Values - Renesas H8SX/1650 Hardware Manual

2.5.7

Multiply-Accumulate Register (MAC)

MAC is a 64-bit register that stores the results of multiply-and-accumulate operations. It consists
of two 32-bit registers denoted MACH and MACL. The lower 10 bits of MACH are valid; the
upper bits are sign-extended.
2.5.8

Initial Register Values

Reset exception handling loads the start address from the vector table into the PC contents, clears
the trace bit in EXR to 0, and sets the interrupt mask bits in CCR and EXR to 1. The other CCR
bits, MAC and the general registers are not initialized. In particular, the stack pointer (ER7) is not
initialized. The stack pointer should therefore be initialized using an MOV.L instruction executed
immediately after a reset.
Rev.2.00 Jun. 28, 2007 Page 29 of 666
REJ09B0311-0200
Section 2 CPU