SH7080_09 Datasheet, PDF (1321/1622 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH RISC engine Family

Section 23 Flash Memory
• The current frequency of the CPU clock is set to the FPEFEQ parameter (general
register R4). For the settable range of the FPEFEQ parameter, see section 28.3.1, Clock
Timing.
When the frequency is set out of this range, an error is returned to the FPFR parameter
of the initialization program and initialization is not performed. For details on the
frequency setting, see the description in section 23.4.3 (2.1), Flash
programming/erasing frequency parameter (FPEFEQ: general register R4 of CPU).
• The start address in the user branch destination is set to the (FUBRA: CPU general
register R5) parameter.
When the user branch processing is not required, 0 must be set to FUBRA.
When the user branch is executed, the branch destination is executed in flash memory
other than the one that is to be programmed. The area of the on-chip program that is
downloaded cannot be set.
The program processing must be returned from the user branch processing by the RTS
instruction.
See the description in section 23.4.3 (2.2), Flash user branch address setting parameter
(FUBRA: general register R5 of CPU).
(2.7) Initialization
When a programming program is downloaded, the initialization program is also downloaded to
on-chip RAM. There is an entry point of the initialization program in the area from (download
start address set by FTDAR) + 32 bytes. The subroutine is called and initialization is executed
by using the following steps.
MOV.L #DLTOP+32,R1
JSR @R1
NOP
; Set entry address to R1
; Call initialization routine
• The general registers other than R0 are saved in the initialization program.
• R0 is a return value of the FPFR parameter.
• Since the stack area is used in the initialization program, a stack area of maximum 128
bytes must be reserved in RAM.
• Interrupts can be accepted during the execution of the initialization program. However,
the program storage area and stack area in on-chip RAM and register values must not
be destroyed.
(2.8) The return value of the initialization program, FPFR (general register R0) is checked.
(2.9) FKEY must be set to H'5A and the user MAT must be prepared for programming.
(2.10) The parameter which is required for programming is set.
Rev. 4.00 Dec. 15, 2009 Page 1261 of 1558
REJ09B0181-0400