M50LPW012 データシートの表示（PDF） - STMicroelectronics
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M50LPW012 Datasheet PDF : 35 Pages
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M50LPW012
Table 3. System Memory Map
A31:24, A22
A23
Array Register
Top
FFh, 1b
1
0
Bottom
00h, 0b
0
1
SIGNAL DESCRIPTIONS
There are two different bus interfaces available on
this part. The active interface is selected before
power-up or during Reset using the Interface Con-
figuration Pin, IC.
The signals for each interface are discussed in the
Low Pin Count (LPC) Signal Descriptions section
and the Address/Address Multiplexed (A/A Mux)
Signal Descriptions section below. The supply sig-
nals are discussed in the Supply Signal Descrip-
tions section below.
Low Pin Count (LPC) Signal Descriptions
For the Low Pin Count (LPC) Interface see Figure
1, Logic Diagram, and Table 1, Signal Names.
Input/Output Communications (LAD0-LAD3). All
Input and Output Communication with the memory
take place on these pins. Addresses and Data for
Bus Read and Bus Write operations are encoded
on these pins.
Input Communication Frame (LFRAME). The
Input Communication Frame (LFRAME) signals
the start of a bus operation. When Input Commu-
nication Frame is Low, VIL, on the rising edge of
the Clock a new bus operation is initiated. If Input
Communication Frame is Low, VIL, during a bus
operation then the operation is aborted. When In-
put Communication Frame is High, VIH, the cur-
rent bus operation is proceeding or the bus is idle.
Identification Inputs (ID0-ID3). The Identification
Inputs (ID0-ID3) allow to address up to 16
memories on a bus. The value on addresses A18-
A21 is compared to the hardware strapping on the
ID0-ID3 pins to select which memory is being
addressed, as shown in Table 2.
General Purpose Inputs (GPI0-GPI4). The Gener-
al Purpose Inputs can be used as digital inputs for
the CPU to read. The General Purpose Input Reg-
ister holds the values on these pins. The pins must
have stable data from before the start of the cycle
that reads the General Purpose Input Register un-
til after the cycle is complete. These pins must not
be left to float, they should be driven Low, VIL, or
High, VIH.
Interface Configuration (IC). The Interface Con-
figuration input selects whether the Low Pin Count
(LPC) or the Address/Address Multiplexed (A/A
Mux) Interface is used. The chosen interface must
be selected before power-up or during a Reset
and, thereafter, cannot be changed. The state of
the Interface Configuration, IC, should not be
changed during operation.
To select the Low Pin Count (LPC) Interface the
Interface Configuration pin should be left to float or
driven Low, VIL; to select the Address/Address
Multiplexed (A/A Mux) Interface the pin should be
driven High, VIH. An internal pull-down resistor is
included with a value of RIL; there will be a leakage
current of ILI2 through each pin when pulled to VIH;
see Table 21.
Interface Reset (RP). The Interface Reset (RP)
input is used to reset the memory. When Interface
Reset (RP) is set Low, VIL, the memory is in Reset
mode: the outputs are put to high impedance and
the current consumption is minimized. When RP is
set High, VIH, the memory is in normal operation.
After exiting Reset mode, the memory enters
Read mode.
CPU Reset (INIT). The CPU Reset, INIT, pin is
used to Reset the memory when the CPU is reset.
It behaves identically to Interface Reset, RP, and
the internal Reset line is the logical OR (electrical
AND) of RP and INIT.
Clock (CLK). The Clock, CLK, input is used to
clock the signals in and out of the Input/Output
Communication Pins, LAD0-LAD3. The Clock
conforms to the PCI specification.
Top Block Lock (TBL). The Top Block Lock
input is used to prevent the Top Block (Block 6)
from being changed. When Top Block Lock, TBL,
is set Low, VIL, Program and Block Erase
operations in the Top Block have no effect,
regardless of the state of the Lock Register. When
Top Block Lock, TBL, is set High, VIH, the
protection of the Block is determined by the Lock
Register. The state of Top Block Lock, TBL, does
not affect the protection of the Main Blocks (Blocks
0 to 5).
Top Block Lock, TBL, must be set prior to a Pro-
gram or Block Erase operation is initiated and
must not be changed until the operation completes
or unpredictable results may occur. Care should
be taken to avoid unpredictable behavior by
changing TBL during Program or Erase Suspend.
Write Protect (WP). The Write Protect input is
used to prevent the Main Blocks (Blocks 0 to 5)
from being changed. When Write Protect, WP, is
set Low, VIL, Program and Block Erase operations
in the Main Blocks have no effect, regardless of
the state of the Lock Register. When Write Protect,
WP, is set High, VIH, the protection of the Block is
determined by the Lock Register. The state of
Write Protect, WP, does not affect the protection of
the Top Block (Block 6).
Write Protect, WP, must be set prior to a Program
or Block Erase operation is initiated and must not
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