R5F61525 RENESAS [Renesas Technology Corp], R5F61525 Datasheet - Page 71

• Manufacturer Part Number: R5F61525
• Description: 32-Bit CISC Microcomputer H8SX Family H8SX/1500 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

2.5.7
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. The MAC contents are changed with the MAC, CLRMAC, LDMAC,
and STMAC instructions.
2.5.8
Reset exception handling loads the start address from the vector table into the PC, clears the T bit
in EXR to 0, and sets the I bits in CCR and EXR to 1. The general registers, MAC, and the other
bits in CCR are not initialized. In particular, the initial value of the stack pointer (ER7) is
undefined. The SP should therefore be initialized using an MOV.L instruction executed
immediately after a reset.
2.6
The H8SX CPU can process 1-bit, 4-bit BCD, 8-bit (byte), 16-bit (word), and 32-bit (longword)
data.
Bit-manipulation instructions operate on 1-bit data by accessing bit n (n = 0, 1, 2, …, 7) of byte
operand data. The DAA and DAS decimal-adjust instructions treat byte data as two digits of 4-bit
BCD data.
2.6.1
Figure 2.12 shows the data formats in general registers.
Multiply-Accumulate Register (MAC)
Initial Values of CPU Registers
2Data Formats
General Register Data Formats
Rev. 3.00 Mar. 14, 2006 Page 33 of 804
REJ09B0104-0300
Section 2 CPU