RL78/D1A User's Manual: Hardware - Renesas

Under development
Preliminary document
Specifications in this document are tentative and subject to change.
RL78/D1A CHAPTER 27 OPTION BYTE
27.4 Setting of Option Byte
The user option byte and on-chip debug option byte can be set using the assembler linker option, in addition to
describing to the source. When doing so, the contents set by using the linker option take precedence, even if descriptions
exist in the source, as mentioned below.
A software description example of the option byte setting is shown below.
OPT CSEG OPT_BYTE
DB 36H ; Does not use interval interrupt of watchdog timer,
; Enables watchdog timer operation,
; Window open period of watchdog timer is 50%,
; Overflow time of watchdog timer is 2 9 /fIL,
; Stops watchdog timer operation during HALT/STOP mode
DB 7AH ; Select 2.75 V for VLVDL
; Select rising edge 2.92 V, falling edge 2.86 V for VLVDH
; Select the interrupt & reset mode as the LVD operation mode
stops clock monitoring
DB 0C9H ; Select the HS (high speed main) mode as the flash operation mode
and 16 MHz as the frequency of the high-speed on-chip oscillator
DB 85H ; Enables on-chip debug operation, does not erase flash memory
data when security ID authorization fails
When the boot swap function is used during self programming, 000C0H to 000C3H is switched to 020C0H to 020C3H.
Describe to 020C0H to 020C3H, therefore, the same values as 000C0H to 000C3H as follows.
OPT2 CSEG AT 020C0H
DB 36H ; Does not use interval interrupt of watchdog timer,
; Enables watchdog timer operation,
; Window open period of watchdog timer is 50%,
; Overflow time of watchdog timer is 2 9 /fIL,
; Stops watchdog timer operation during HALT/STOP mode
DB 7AH ; Select 2.75 V for VLVDL
; Select rising edge 2.92 V, falling edge 2.86 V for VLVDH
; Select the interrupt & reset mode as the LVD operation mode
stops clock monitoring
DB 0C9H ; Select the HS (high speed main) mode as the flash operation mode
and 16 MHz as the frequency of the high-speed on-chip oscillator
DB 85H ; Enables on-chip debug operation, does not erase flash memory
data when security ID authorization fails
Caution To specify the option byte by using assembly language, use OPT_BYTE as the relocation attribute
name of the CSEG pseudo instruction. To specify the option byte to 020C0H to 020C3H in order to
use the boot swap function, use the relocation attribute AT to specify an absolute address.
R01UH0317EJ0004 Rev. 0.04 1159
Feb. 22, 2013