AT49LL080 Datasheet, PDF (5/31 Pages) ATMEL Corporation – 8-megabit Low-pin Count Flash Memory

AT49LL080
Table 1. Pin Description (Continued)
Interface
Symbol
Type
LPC
A/A Mux
GNDa
SUPPLY
X
X
RFU
X
NC
X
X
RY/BY
OUTPUT
X
Name and Function
ANALOG GROUND: Should be tied to same plane as GND.
RESERVED FOR FUTURE USE: These pins are reserved for future
generations of this product and should be connected accordingly. These pins
may be left disconnected or driven. If they are driven, the voltage levels should
meet V_IH and V_IL requirements.
A/A Mux = I/O[7:4]
NO CONNECT: Pin may be driven or floated. If it is driven, the voltage levels
should meet V_IH and V_IL.
READY/BUSY: Valid only in A/A Mux Mode. This output pin is a reflection of bit
7 in the status register. This pin is used to determine sector erase or program
completion.
Low Pin Count
Interface (LPC)
Table 2 lists the seven required signals used for the LPC interface.
Table 2. LPC Required Signal List
Direction
Signal
Peripheral Master Description
LAD[3:0]
I/O
I/O Multiplexed command, address and data
LFRAME
I
O
Indicates start of a new cycle, termination of broken
cycle.
RST
I
I
Reset: Same as PCI Reset on the master. The master
does not need this signal if it already has PCIRST on its
interface.
CLK
I
I
Clock: Same 33 MHz clock as PCI clock on the master.
Same clock phase with typical PCI skew. The master
does not need this signal if it already has PCICLK on its
interface.
LAD[3:0]: The LAD[3:0] signal lines communicate address, control, and data informa-
tion over the LPC bus between a master and a peripheral. The information
communicated are: start, stop (abort a cycle), transfer type (memory, I/O, DMA), trans-
fer direction (read/write), address, data, wait states, DMA channel, and bus master
grant.
LFRAME: LFRAME is used by the master to indicate the start of cycles and the termina-
tion of cycles due to an abort or time-out condition. This signal is to be used be by
peripherals to know when to monitor the bus for a cycle.
The LFRAME signal is used as a general notification that the LAD[3:0] lines contain
information relative to the start or stop of a cycle, and that peripherals must monitor the
bus to determine whether the cycle is intended for them. The benefit to peripherals of
LFRAME is, it allows them to enter lower power states internally.
When peripherals sample LFRAME active, they are to immediately stop driving the
LAD[3:0] signal lines on the next clock and monitor the bus for new cycle information.
RESET: RST or INIT at VIL initiates a device reset. In read mode, RST or INIT low
deselects the memory, places output drivers in a high-impedance state, and turns off all
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