Datasheet

78K0/Ix2 CHAPTER 3 CPU ARCHITECTURE
R01UH0010EJ0500 Rev.5.00 48
Feb 28, 2012
(2) CALLT instruction table area
The 64-byte area 0040H to 007FH can store the subroutine entry address of a 1-byte call instruction (CALLT).
(3) Option byte area
A 5-byte area of 0080H to 0084H and 1080H to 1084H can be used as an option byte area. Set the option byte at
0080H to 0084H when the boot swap is not used, and at 0080H to 0084H and 1080H to 1084H when the boot swap is
used. For details, refer to CHAPTER 24 OPTION BYTE.
(4) On-chip debug security ID setting area
A 10-byte area of 0085H to 008EH and 1085H to 108EH can be used as an on-chip debug security ID setting area. Set
the on-chip debug security ID of 10 bytes at 0085H to 008EH when the boot swap is not used and at 0085H to 008EH
and 1085H to 108EH when the boot swap is used. For details, refer to CHAPTER 26 ON-CHIP DEBUG FUNCTION.
(5) CALLF instruction entry area
The area 0800H to 0FFFH can perform a direct subroutine call with a 2-byte call instruction (CALLF).
3.1.2 Internal data memory space
7
8K0/Ix2 microcontrollers incorporate the following RAMs.
(1) Internal high-speed RAM
Table 3-5. Internal High-Speed RAM Capacity
Product
78K0/IY2 78K0/IA2 78K0/IB2
Internal High-Speed RAM
 PD78F0740, 78F0750
 
384  8 bits (FD80H to FEFFH)
 PD78F0741, 78F0751  PD78F0743, 78F0753  PD78F0745, 78F0755 512  8 bits (FD00H to FEFFH)
 PD78F0742, 78F0752  PD78F0744, 78F0754  PD78F0746, 78F0756 768  8 bits (FC00H to FEFFH)
The 32-byte area FEE0H to FEFFH is assigned to four general-purpose register banks consisting of eight 8-bit registers
per bank.
This area cannot be used as a program area in which instructions are written and executed.
The internal high-speed RAM can also be used as a stack memory.
3.1.3 Special function register (SFR) area
On
-chip peripheral hardware special function registers (SFRs) are allocated in the area FF00H to FFFFH (refer to Tables
3-6 to 3-9 Special Function Register List in 3.2.3 Special function registers (SFRs)).
Caution Do not access addresses to which SFRs are not assigned.