h8s-2649 Renesas Electronics Corporation., h8s-2649 Datasheet - Page 63

• Manufacturer Part Number: h8s-2649
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

2.4.2
This 24-bit counter indicates the address of the next instruction the CPU will execute. The length
of all CPU instructions is 2 bytes (one word), so the least significant PC bit is ignored. (When an
instruction is fetched, the least significant PC bit is regarded as 0).
2.4.3
EXR is an 8-bit register that manipulates the LDC, STC, ANDC, ORC, and XORC instructions.
When these instructions, except for the STC instruction, are executed, all interrupts including NMI
will be masked for three states after execution is completed.
Bit
7
6 to 3
2
1
0
Program Counter (PC)
Extended Control Register (EXR)
Bit Name
T

I2
I1
I0
0
Initial
Value
All 1
1
1
1
SP (ER7)
R/W
R/W

R/W
R/W
R/W
Figure 2.8 Stack
Reserved
These bits are always read as 1.
Description
Trace Bit
When this bit is set to 1, a trace exception is generated
each time an instruction is executed. When this bit is
cleared to 0, instructions are executed in sequence.
These bits designate the interrupt mask level (0 to 7).
For details, refer to section 5, Interrupt Controller.
Rev. 2.00 Dec. 05, 2005 Page 25 of 724
Stack area
Free area
REJ09B0200-0200
Section 2 CPU