MBM29LV400TC-70/-90/-12/MBM29LV400BC-70/-90/-12
Extended Command
(1) Fast Mode
MBM29LV400TC/BC has Fast Mode function. This mode dispenses with the initial two unclock cycles
required in the standard program command sequence by writing Fast Mode command into the command
register. In this mode, the required bus cycle for programming is two cycles instead of four bus cycles in
standardprogramcommand. (Donotwriteerasecommandinthismode.)Thereadoperationisalsoexecuted
afterexitingthismode. Toexitthismode, itisnecessarytowriteFastModeResetcommandintothecommand
register. (Refer to the Figure 27 Extended algorithm.) The VCC active current is required even CE = VIH during
Fast Mode.
(2) Fast Programming
During Fast Mode, the programming can be executed with two bus cycles operation. The Embedded Program
Algorithm is executed by writing program set-up command (A0H) and data write cycles (PA/PD). (Refer to
the Figure 27 Extended algorithm.)
(3) Extended Sector Protection
Inadditiontonormalsectorprotection, theMBM29LV400TC/BChasExtendedSectorProtectionasextended
function. This function enable to protect sector by forcing VID on RESET pin and write a commnad sequence.
Unlike conventional procedure, it is not necessary to force VID and control timing for control pins. The only
RESET pinrequiresVID forsectorprotectioninthismode. TheextendedsectorprotectrequiresVID onRESET
pin. With this condition, the operation is initiated by writing the set-up command (60H) into the command
register. Then, the sector addresses pins (A17, A16, A15, A14, A13 and A12) and (A6, A1, A0) = (0, 1, 0) should
be set to the sector to be protected (recommend to set VIL for the other addresses pins), and write extended
sector protect command (60H). A sector is typically protected in 150 µs. To verify programming of the
protection circuitry, the sector addresses pins (A17, A16, A15, A14, A13 and A12) and (A6, A1, A0) = (0, 1, 0) should
be set and write a command (40H). Following the command write, a logical “1” at device output DQ0 will
produce for protected sector in the read operation. If the output data is logical “0”, please repeat to write
extended sector protect command (60H) again. To terminate the operation, it is necessary to set RESET
pin to VIH.
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