R8CSLASH20 datasheet(422/501 Pages) RENESAS

422 / 501 page

R8C/20 Group, R8C/21 Group

19. Flash Memory

Rev.2.00 Aug 27, 2008

Page 406 of 458

REJ09B0250-0200

NOTES:

1. Do not use the address match interrupt while the command is executed because the vector of the

address match interrupt is allocated on ROM.

2. Do not use the non-maskable interrupt while block 0 is automatically erased because the fixed

vector is allocated block 0.

19.7.1.4

How to Access

Write 0 to the corresponding bits before writing 1 when setting the FMR01, FMR02, or FMR11 bit to 1. Do not

generate an interrupt between writing 0 and 1.

19.7.1.5

Rewriting User ROM Area

In EW0 mode, if the power supply voltage drops while rewriting any block in which the rewrite control

program is stored, the flash memory may not be able to be rewritten because the rewrite control program cannot

be rewritten correctly. In this case, use standard serial I/O mode.

19.7.1.6

Program

Do not write additions to the already programmed address.

Table 19.10

EW1 Mode Interrupts

Mode

Status

When Maskable Interrupt

Request is Acknowledged

When Watchdog Timer, Oscillation

Stop Detection and Voltage Monitor 2

Interrupt Request are Acknowledged

EW1 During automatic erasing

(erase- suspend function

is enabled)

The auto-erasing is suspended

after td(SR-SUS) and the

interrupt process is executed.

The auto-erasing can be

restarted by setting the FMR41

bit in the FMR4 register to 0

(erase restart) after the

interrupt process completes.

Once an interrupt request is

acknowledged, the auto-

programming or auto-erasing is

forcibly stopped immediately and

resets the flash memory. An interrupt

process starts after the fixed period

and the flash memory restarts. Since

the block during the auto-erasing or

the address during the auto-

programming is forcibly stopped, the

normal value may not be read.

Execute the auto-erasing again and

ensure the auto-erasing is completed

normally.

Since the watchdog timer does not

stop during the command operation,

the interrupt request may be

generated. Reset the watchdog timer

regularly using the erase-suspend

function.

During automatic erasing

(erase- suspend function

is disabled)

The auto-erasing has a priority

and the interrupt request

acknowledgement is waited.

The interrupt process is

executed after the auto-erasing

completes.

During automatic

programming

(program suspend

function enabled)

The auto-programming is

suspended after td(SR-SUS)

and the interrupt process is

executed. The auto-

programming can be restarted

by setting the FMR42 bit in the

FMR4 register to 0 (program

restart) after the interrupt

process completes.

Auto programming

(program suspend

function disabled)

The auto-programming has a

priority and the interrupt

request acknowledgement is

waited. The interrupt process is

executed after the auto-

programming completes.

R8C/20 Datasheet(PDF) 422 Page - Renesas Technology Corp

R8C/20 Datasheet(HTML) 422 Page - Renesas Technology Corp

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL