UPD78F0838 Renesas Electronics Corporation., UPD78F0838 Datasheet - Page 83

• Manufacturer Part Number: UPD78F0838
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

(2) CALLT instruction table area
(3) Option byte area
(4) CALLF instruction entry area
(5) On-chip debug security ID setting area
3.1.2 Internal data memory space
(1) Internal high-speed RAM
(2) Internal expansion RAM
78K0/Dx2 products incorporate the following RAM.
The 64-byte area 0040H to 007FH can store the subroutine entry address of a 1-byte call instruction (CALLT).
The option byte area is assigned to the 1-byte area of 0080H. Refer to CHAPTER 25 OPTION BYTE for details.
The area 0800H to 0FFFH can perform a direct subroutine call with a 2-byte call instruction (CALLF).
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, see CHAPTER 27 ON-CHIP
DEBUG FUNCTION.
The 32-byte area FEE0H to FEFFH is assigned to four general-purpose register banks consisting of eight 8-bit
registers per one 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.
The internal expansion RAM can also be used as a normal data area similar to the internal high-speed RAM, as
well as a program area in which instructions can be written and executed.
The internal expansion RAM cannot be used as a stack memory.
PD78F0836
PD78F0837
PD78F0844
PD78F0845
PD78F0836, 78F0844
PD78F0837, 78F0845
78K0/DE2
78K0/DE2
Part Number
Part Number
PD78F0838, 78F0840, 78F0842
PD78F0839, 78F0841, 78F0843
PD78F0846, 78F0848
PD78F0847, 78F0849
Table 3-5. Internal High-Speed RAM Capacity
Table 3-6. Internal Expansion RAM Capacity
78F0842, 78F0846, 78F0848
78F0843, 78F0847, 78F0849
PD78F0838, 78F0840,
PD78F0839, 78F0841,
Preliminary User’s Manual U19748EJ1V0UD
CHAPTER 3 CPU ARCHITECTURE
78K0/DF2
78K0/DF2
1024
1024
2048
8 bits (FB00H to FEFFH)
8 bits (F400H to F7FFH)
8 bits (F000H to F7FFH)
Internal High-Speed RAM
Internal Expansion RAM
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