Datasheet

©2011 Silicon Storage Technology, Inc. DS25029A 06/11
14
16 Mbit LPC Serial Flash
SST49LF016C
Data Sheet
A
Microchip Technology Company
Abort Mechanism
If LFRAME# is driven low for one or more clock cycles after the start of a bus cycle, the cycle will be
terminated. The host may drive the LAD[3:0] with ‘1111b’ (ABORT nibble) to return the interface to
ready mode. The ABORT only affects the current bus cycle. For a multi-cycle command sequence,
such as the Erase or Program commands, ABORT doesn’t interrupt the entire command sequence,
only the current bus cycle of the command sequence. The host can re-send the bus cycle for the
aborted command and continue the command sequence after the device is ready again.
Response to Invalid Fields for Firmware Memory Cycle
During an on-going Firmware Memory bus cycle, the SST49LF016C will not explicitly indicate that it
has received invalid field sequences. The response to specific invalid fields or sequences is described
as follows:
ID mismatch:
If the IDSEL field does not match ID[3:0], the device will ignore the cycle. See “Multiple Device Selec-
tion for Firmware Memory Cycle” on page 15 for details.
Address out of range:
The address sequence is 7 fields long (28 bits) with Firmware Memory bus cycles. Only some of the
address fields bits are decoded by the SST49LF016C. These are: A
0
through A
20
and A
22.
Address
A
22
has the special function of directing reads and writes to the flash core (A
22
=1) or to the register
space (A
22
=0).
Invalid MSIZE field:
If the SST49LF016C receives an invalid size field during a Firmware Memory Read or Write operation,
the device will reset and no operation will be attempted. The device will not generate any kind of
response in this situation. The SST49LF016C will only respond to values listed in Table 6.
Once valid START, IDSEL, and MSIZE are received, the SST49LF016C will always complete the bus
cycle. However, if the device is busy performing a flash Erase or Program operation, no new internal
memory Write will be executed. As long as the states of LAD[3:0] and LFRAME# are known, the
response of the ST49LF016C to signals received during the cycle is predictable.
Table 6: Valid MSIZE field Values for Firmware Memory Cycles
MSIZE Direction Size of Transfer
0000 R/W 1 Byte
0001 R/W 2 Byte
0010 R/W 4 Byte
0100 R 16 Byte
0111 R 128 Byte
T6.0 25029