FEDL22620-01
ML22620
●
Serial flash memory rewrite function
The serial flash memory can be rewritten in the following two ways.
①
Rewrite using the clock synchronous serial interface of the MCU command interface
By using the CSB, SCK, SI and SO pins, which are clock synchronous serial interfaces of the MCU command interface the
serial flash memory can be rewritten. When the PUP command and FDIRECT command are entered with the EROFF pin set
to "L", direct access to the serial flash memory is enabled from the CSB, SCK, SI and SO pins.
For the PUP command, refer to the "PUP command" in the "Command" section. For the FDIRECT command, refer to the
"FDIRECT command" in the "Command" section.
②
Rewrite using serial flash memory interface without this LSI
The serial flash memory can be rewritten using the ERCSB, ERSCK, ERSI and ERSO pins that is the serial flash memory
interface.
When the EROFF pin set to "H", the serial flash memory can be rewritten using the ERCSB, ERSCK, ERSI and ERSO
pins without this LSI. ( ERCSB, ERSCK and ERSO pins are in a condition of high-impedance. )
CSB
Status
SCK
SI
FDIRECT command
1
st
byte
CBUSYB
t
CB1
FDIRECT command
2
nd
byte
Serial flash memory access mode
t
PUP
PUP command
EROFF
“L”
Direct access to the serial flash
memory is enabled
t
CB1
Normal mode
VOH
VOL
EROFF
Status
Hi-Z Status
ERSCK
ERSO
Output Status
VOH
VOL
VOH
VOL
t
EFLH
ERCSB
VIH
VIL
Hi-Z
Hi-Z
Hi-Z
EROFF
ERCSB
ERSCK
ERSO
ERSI
CSB
SCK
SI
SO
SOUND LSI
①
MCU Command
Interface
②
Serial flash memory Interface
Serial flash memory
CSB
SCK
SI
SO
Flash memory writer
etc.
34/115
Summary of Contents for LAPIS Semiconductor ML22620
Page 106: ...FEDL22620 01 ML22620 106 115...