Section 2 CPU
Rev.2.00 Jun. 28, 2007 Page 26 of 666
REJ09B0311-0200
Free area
Stack area
SP (ER7)
Figure 2.11 Stack
2.5.2 Program
Counter
(PC)
PC is a 32-bit counter that indicates the address of the next instruction the CPU will execute. The
length of all CPU instructions is two bytes (one word) or a multiple of two bytes, so the least
significant PC bit is ignored. When an instruction is fetched, the least significant PC bit is
regarded as 0.
2.5.3
Condition-Code Register (CCR)
CCR is an 8-bit register that contains internal CPU status information, including an interrupt mask
(I) and user (UI, U) bits and half-carry (H), negative (N), zero (Z), overflow (V), and carry (C)
flags.
Operations can be performed on the CCR bits by the LDC, STC, ANDC, ORC, and XORC
instructions. The N, Z, V, and C flags are used as branching conditions for conditional branch
(Bcc) instructions.
Bit Bit
Name
Initial
Value R/W
Description
7
I
1
R/W
Interrupt Mask Bit
Masks interrupts when set to 1. This bit is set to 1 at the
start of an exception-handling sequence.
6
UI
Undefined R/W
User Bit or Interrupt Mask Bit
Can be written and read by software using the LDC,
STC, ANDC, ORC, and XORC instructions. This bit can
also be used as an interrupt mask bit.
Summary of Contents for H8SX/1650
Page 2: ...Rev 2 00 Jun 28 2007 Page ii of xxii...
Page 106: ...Section 4 Exception Handling Rev 2 00 Jun 28 2007 Page 84 of 666 REJ09B0311 0200...
Page 142: ...Section 5 Interrupt Controller Rev 2 00 Jun 28 2007 Page 120 of 666 REJ09B0311 0200...
Page 326: ...Section 8 I O Ports Rev 2 00 Jun 28 2007 Page 304 of 666 REJ09B0311 0200...
Page 470: ...Section 12 Watchdog Timer WDT Rev 2 00 Jun 28 2007 Page 448 of 666 REJ09B0311 0200...
Page 566: ...Section 14 A D Converter Rev 2 00 Jun 28 2007 Page 544 of 666 REJ09B0311 0200...
Page 574: ...Section 16 RAM Rev 2 00 Jun 28 2007 Page 552 of 666 REJ09B0311 0200...
Page 584: ...Section 17 Clock Pulse Generator Rev 2 00 Jun 28 2007 Page 562 of 666 REJ09B0311 0200...
Page 638: ...Section 19 List of Registers Rev 2 00 Jun 28 2007 Page 616 of 666 REJ09B0311 0200...
Page 668: ...Section 20 Electrical Characteristics Rev 2 00 Jun 28 2007 Page 646 of 666 REJ09B0311 0200...
Page 676: ...Appendix Rev 2 00 Jun 28 2007 Page 654 of 666 REJ09B0311 0200...
Page 688: ...Rev 2 00 Jun 28 2007 Page 666 of 666 REJ09B0311 0200...
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