Datasheet

Section 2 CPU
Rev.6.00 Mar. 18, 2009 Page 34 of 980
REJ09B0050-0600
2.4.5 Initial Register Values
Reset exception handling loads the CPU's program counter (PC) from the vector table, clears the
trace (T) bit in EXR to 0, and sets the interrupt mask (I) bits in CCR and EXR to 1. The other
CCR bits and the general registers are not initialized. Note that the stack pointer (ER7) is
undefined. The stack pointer should therefore be initialized by an MOV.L instruction executed
immediately after a reset.
2.5 Data Formats
The H8S/2000 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.
2.5.1 General Register Data Formats
Figure 2.9 shows the data formats of general registers.
70
70
MSB LSB
MSB LSB
7043
Don't care
Don't care
Don't care
7043
70
Don't care
65432710
70
Don't care
65432710
Don't care
RnH
RnL
RnH
RnL
RnH
RnL
Data Type Register Number Data Format
Byte data
Byte data
4-bit BCD data
4-bit BCD data
1-bit data
1-bit data
Upper Lower
Upper Lower
Figure 2.9 General Register Data Formats (1)