S70WS512N00 Datasheet, PDF (48/93 Pages) SPANSION – Same-Die Stacked Multi-Chip Product (MCP) 512 Megabit (32M x 16 bit) CMOS 1.8 Volt-only Simultaneous Read/Write, Burst-mode Flash Memory

Advance Information
8.9 Hardware Reset
The RESET# input provides a hardware method of resetting the device to reading array data.
When RESET# is driven low for at least a period of t_RP, the device immediately terminates any
operation in progress, tristates all outputs, resets the configuration register, and ignores all read/
write commands for the duration of the RESET# pulse. The device also resets the internal state
machine to reading array data.
To ensure data integrity the operation that was interrupted should be reinitiated once the device
is ready to accept another command sequence.
When RESET# is held at V_SS, the device draws CMOS standby current (I_CC4). If RESET# is held
at V_IL, but not at V_SS, the standby current is greater.
RESET# may be tied to the system reset circuitry which enables the system to read the boot-up
firmware from the Flash memory upon a system reset.
See Figures 12.5 and 12.12 for timing diagrams.
8.10
Software Reset
Software reset is part of the command set (see Table 13.1) that also returns the device to array
read mode and must be used for the following conditions:
1. to exit Autoselect mode
2. when DQ5 goes high during write status operation that indicates program or erase cycle was
not successfully completed
3. exit sector lock/unlock operation.
4. to return to erase-suspend-read mode if the device was previously in Erase Suspend mode.
5. after any aborted operations
Software Functions and Sample Code
Cycle
Reset Command
Note: Base = Base Address.
Table 8.24 Reset
(LLD Function = lld_ResetCmd)
Operation
Byte Address
Write
Base + xxxh
Word Address
Base + xxxh
Data
00F0h
The following is a C source code example of using the reset function. Refer to the Spansion
Low Level Driver User’s Guide (available on www.amd.com and www.fujitsu.com) for general
information on Spansion Flash memory software development guidelines.
/* Example: Reset (software reset of Flash state machine) */
*( (UINT16 *)base_addr + 0x000 ) = 0x00F0;
The following are additional points to consider when using the reset command:
„ This command resets the banks to the read and address bits are ignored.
„ Reset commands are ignored once erasure has begun until the operation is complete.
„ Once programming begins, the device ignores reset commands until the operation is com-
plete
„ The reset command may be written between the cycles in a program command sequence be-
fore programming begins (prior to the third cycle). This resets the bank to which the system
was writing to the read mode.
March 14, 2005 S70WS512N00_00_A0
S70WS512N00 Based MCPs
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