CAT28F001 CATALYST [Catalyst Semiconductor], CAT28F001 Datasheet - Page 11

• Manufacturer Part Number: CAT28F001
• Description: 1 Megabit CMOS Boot Block Flash Memory
• Manufacturer: CATALYST [Catalyst Semiconductor]

IN-SYSTEM OPERATION
For on-board programming, the RP pin is the most
convenient means of altering the boot block. Before
issuing Program or Erase confirms commands, RP must
transition to V
the program or erase interval (until after Status Register
confirm of successful completion). At this time, it can
return to V
Figure 4 Byte Programming Flowchart
FULL STATUS CHECK PROCEDURE
STATUS REGISTER DATA
IH
CHECK IF DESIRED
or V
READ (SEE ABOVE)
HH
BYTE PROGRAM
BYTE PROGRAM
BYTE ADDRESS
ADDRESS/DATA
READ STATUS
SUCCESSFUL
FULL STATUS
. Hold RP at this high voltage throughout
WRITE BYTE
COMPLETED
WRITE 40H,
REGISTER
IL
SR.7 = 1?
SR.3 = 0?
SR.4 = 0?
.
START
YES
YES
YES
NO
NO
NO
BYTE PROGRAM
V
PP
ERROR
ERROR
RANGE
11
Repeat for subsequent bytes.
Full Status check can be done after each byte or after a sequence
of bytes.
Write FFH after the last byte programming operation to reset the
device to Read Array Mode.
SR.3 MUST be cleared, if set during a program attempt, before
further attempts are allowed by the Write State Machine.
SR.3 is only cleared by the Clear Status Register Command, in
case where multiple bytes are programmed before full status is
checked.
If error is detected, clear the Status Register before attempting retry
or other error recovery.
Bus
Operation
Write
Write
Read
Standby
Bus
Operation
Standby
Standby
Command
Program
Setup
Program
Command
Comments
Data = 40H
Address = Bytes to be Programmed
Data to be programmed
Address = Byte to be Programmed
Status Register Data.
Toggle OE or CE to update
Status Register
Check SR.7
1 = Ready, 0 = Busy
Comments
Check SR.3
1 = V
Check SR.3
1 = Byte Program Error
PP
Low Detect
Doc. No. 25071-00 2/98 F-1
CAT28F001