X5114 Datasheet, PDF (8/40 Pages) Xicor Inc. – System Controller

X5114
WMH
NONVOLATILE
Write Memory High
The Write Memory High instruction allows users to write
new data to the upper half of the memory array from
$100h to $1FFh. Its function is similar to Write Memory
Low.
SWEL
VOLATILE
Set Write Enable Latch
The Set Write Enable Latch instruction sets the Write
Enable Latch. This instruction must be completed before
any nonvolatile write cycle operation can begin. Setting
the WEL is not required prior to a write to a volatile
Figure 3. Read Memory (RML or RMH)
register. Setting the Write Enable Latch sets the WEL flag
in the Status Register (SR) to “1”. The Write Enable Latch
remains set until a Reset WEL instruction, the device
powers down, or the completion of a nonvolatile write
operation.
RWEL
VOLATILE
Reset Write Enable Latch
The Reset Write Enable Latch instruction resets the
Write Enable Latch. Resetting the Write Enable Latch
resets the WEL flag in the Status Register (SR) to “0”.
The WEL bit LOW inhibits any nonvolatile memory write
operation.
CSa/CSb
SIa/SIb
SOa/SOb
Device Instruction Memory
Address Opcode Address
SR
Data
Memory
Data-1st
••••••••
Memory
Data-512nd
Figure 4. Write Memory (WML or WMH)
CSa/CSb
SIa, SIb
SOa, SOb
Device Instruction Memory
Address Opcode Address
SR
Data
Memory
Data-1st
••••••••
Memory ^Nonvolatile
Data-32nd _{Write Cycle}
Figure 5. Set/Reset Write Enable Latch (SWEL/RWEL)
CSa/CSb
SIa/SIb
SOa/SOb
Device Instruction
Address Opcode
SR
Data
8