TC58FVT641 datasheet(9/53 Pages) TOSHIBA

9 / 53 page

TC58FVT641/B641FT/XB-70,-10

2001-09-06

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Auto-Program Mode

The TC58FVT641/B641 can be programmed in either byte or word units. Auto-Program Mode is set using the

Program command. The program address is latched on the falling edge of the WE signal and data is latched

on the rising edge of the fourth Bus Write cycle (with WE control). Auto programming starts on the rising edge

of the WE signal in the fourth Bus Write cycle. The Program and Program Verify commands are automatically

executed by the chip. The device status during programming is indicated by the Hardware Sequence flag. To

read the Hardware Sequence flag, specify the address to which the Write is being performed

During Auto Program execution, a command sequence for the bank on which execution is being performed

cannot be accepted. To terminate execution, use a hardware reset. Note that if the Auto-Program operation is

terminated in this manner, the data written so far is invalid.

Any attempt to program a protected block is ignored. In this case the device enters Read Mode 3 µs after the

rising edge of the WE signal in the fourth Bus Write cycle.

If an Auto-Program operation fails, the device remains in the programming state and does not automatically

return to Read Mode. The device status is indicated by the Hardware Sequence flag. Either a Reset command or

a hardware reset is required to return the device to Read Mode after a failure. If a programming operation fails,

the block which contains the address to which data could not be programmed should not be used.

The device allows 0s to be programmed into memory cells which contain a 1. 1s cannot be programmed into

cells which contain 0s. If this is attempted, execution of Auto Program will fail. This is a user error, not a device

error. A cell containing 0 must be erased in order to set it to 1.

Fast Program Mode

Fast Program is a function which enables execution of the command sequence for the Auto Program to be

completed in two cycles. In this mode the first two cycles of the command sequence, which normally requires

four cycles, are omitted. Writing is performed in the remaining two cycles. To execute Fast Program, input the

Fast Program command. Write in this mode uses the Fast Program command but operation is the same at that

for ordinary Auto-Program. The status of the device is indicated by the Hardware Sequence flag and read

operations can be performed as usual. To exit this mode, the Fast Program Reset command must be input.

When the command is input, the device will return to Read Mode.

Acceleration Mode

The TC58FVT641/B641 features Acceleration Mode which allows write time to be reduced. Applying VACC to

WP or ACC automatically sets the device to Acceleration Mode. In Acceleration Mode, Block Protect Mode

changes to Temporary Block Unprotect Mode. Write Mode changes to Fast Program Mode. Modes are switched

by the

/ACC

signal; thus, there is no need for a Temporary Block Unprotect operation or to set or reset Fast

Program Mode. Operation of Write is the same as in Auto-Program Mode. Removing VACC from

/ACC

terminates Acceleration Mode.

TC58FVT641 Scheda tecnica(PDF) 9 Page - Toshiba Semiconductor