MPC89X52AE 参数 Datasheet PDF下载

IFMT

←

xxxxx010

b

ISPCR

←

100xx010

b

IFADRH

←

(Address high byte)

IFADRL

←

(Address low byte)

IFD

←

(byte date to be written into flash)

SCMD

←

46h

SCMD

←

B9h

(CPU progressing will be hold here)

(CPU continues)

/* choice byte-programming command */

/* set ISPEN=1 to enable flash change.

set WAIT=010, 60 MC; assumed 10M X’s*/

/* specify the address to be programmed */

/* prepare data source */

/* trig ISP activity */

Program a byte into flash

IFMT

←

xxxxx001

b

ISPCR

←

100xx010

b

/* choice byte-read command */

/* set ISPEN=1 to enable flash change.

set WAIT=010, 11 MC; assumed 10M X’s*/

/* specify the address to be read */

IFADRH

←

(Address high byte)

IFADRL

←

(Address low byte)

SCMD

←

46h

/* trig ISP activity */

SCMD

←

B9h

(CPU progressing will be hold here)

(CPU continues and currently

IFD

contain the desired data byte )

Read a byte from flash

Booting Program Entrance

The MPC89x52A boots according to the following rule.

If

(

HWBS

== 0 )

&&

( {

ISPAS1, ISPAS0}

≠

{

1, 1

})

System will boot from ISP program

else

System will boot from normal AP program

Above rule is adaptive only for power-up procedure, while not software reset.

Switching from ISP program to AP program

The device permits the user normally start running the AP program as soon as the ISP program

has finished updating the flash content. Just program an instruction at the tail of ISP program as

ISPCR

←

001xxxxx

b

30

MPC89x52A Data Sheet

MEGAWIN