Rainbow Electronics AT45DB642 User Manual

Features

• Single 2.7V - 3.6V Supply

• Dual-interface Architecture

– Dedicated Serial Interface (SPI Modes 0 and 3 Compatible) – Dedicated Parallel I/O Interface (Optional Use)

• Page Program Operation

– Single Cycle Reprogram (Erase and Program) – 8192 Pages (1056 Bytes/Page) Main Memory

• Supports Page and Block Erase Operations

• Two 1056-byte SRAM Data Buffers – Allows Receiving of Data

while Reprogramming the Flash Array

• Continuous Read Capability through Entire Array

– Ideal for Code Shadowing Applications

• Low-power Dissipation

– 4 mA Active Read Current Typical – 2 µA CMOS Standby Current Typical

• 20 MHz Maximum Clock Frequency – Serial Interface

• 5 MHz Maximum Clock Frequency – Parallel Interface

• Hardware Data Protection

• Commercial and Industrial Temperature Ranges

Description

The AT45DB642 is a 2.7-volt only, dual-interface Flash memory ideally suited for a wide variety of digital voice-, image-, program code- and data-storage applications. The dual-interface of the AT45DB642 allows a dedicated serial interface to be connected to a DSP and a dedicated parallel interface to be connected to a microcontroller or vice versa.

64-megabit

2.7-volt Only Dual-interface DataFlash

AT45DB642

Pin Configurations

Pin Name Function

SCK/CLK Serial Clock/Clock

SI Serial Input

SO Serial Output

I/O7 - I/O0 Parallel Input/Output

RESET

RDY/BUSY

SER/PAR

Chip Select

Hardware Page Write Protect Pin

Chip Reset

Ready/Busy

Serial/Parallel Interface Control

DataFlash Card

7654321

(1)

TSOP Top View

Typ e 1

RESET

VCC GND

SCK/CLK

SO*

3 4 5

9 10 11

16 17

SI*

18 19

RDY/BUSY

Note: *Optional Use – See pin description

text for connection information.

I/O7*

I/O6*

I/O5*

I/O4*

VCCP*

GNDP*

I/O3*

I/O2*

I/O1*

I/O0*

SER/PAR*

Note: 1. See AT45DCB008 Datasheet.

Rev. 1638F–DFLSH–09/02

However, the use of either interface is purely optional. Its 69,206,016 bits of memory are organized as 8192 pages of 1056 bytes each. In addition to the main memory, the AT45DB642 also contains two SRAM data buffers of 1056 bytes each. The buffers allow receiving of data while a page in the main memory is being reprogrammed, as well as reading or writing a continuous data stream. EEPROM emulation (bit or byte alterability) is easily handled with a selfcontained three step Read-Modify-Write operation. Unlike conventional Flash memories that are accessed randomly with multiple address lines and a parallel interface, the DataFlash uses either a serial interface or a parallel interface to sequentially access its data. The simple sequential access facilitates hardware layout, increases system reliability, minimizes switching noise, and reduces package size and active pin count. DataFlash supports SPI mode 0 and mode 3. The device is optimized for use in many commercial and industrial applications where high-density, low-pin count, low-voltage, and low-power are essential. The device operates at clock frequencies up to 20 MHz with a typical active read current consumption of 4 mA.

To allow for simple in-system reprogrammability, the AT45DB642 does not require high input voltages for programming. The device operates from a single power supply, 2.7V to 3.6V, for both the program and read operations. The AT45DB642 is enabled through the chip select pin (CS

) and accessed via a three-wire interface consisting of the Serial Input (SI), Serial Output (SO), and the Serial Clock (SCK), or a parallel interface consisting of the parallel input/output pins (I/O7 - I/O0) and the clock pin (CLK). The SCK and CLK pins are shared and provide the same clocking input to the DataFlash.

All programming cycles are self-timed, and no separate erase cycle is required before programming.

When the device is shipped from Atmel, the most significant page of the memory array may not be erased. In other words, the contents of the last page may not be filled with FFH.

Block Diagram

Memory Array

PAGE (1056 BYTES)

SCK/CLK

RESET

VCC

GND

RDY/BUSY

SER/PAR

FLASH MEMORY ARRAY

I/O INTERFACE

SOSI

BUFFER 2 (1056 BYTES)BUFFER 1 (1056 BYTES)

I/O7 - I/O0

To provide optimal flexibility, the memory array of the AT45DB642 is divided into three levels of granularity comprising of sectors, blocks and pages. The “Memory Architecture Diagram” illustrates the breakdown of each level and details the number of pages per sector and block. All program operations to the DataFlash occur on a page-by-page basis; however, the optional erase operations can be performed at the block or page level.

AT45DB642

1638F–DFLSH–09/02

AT45DB642

Memory Architecture Diagram

SECTOR ARCHITECTURE BLOCK ARCHITECTURE PAGE ARCHITECTURE

SECTOR 0 = 8 Pages 8448 bytes (8K + 256)

SECTOR 1 = 248 Pages

261,888 bytes (248K + 7936)

SECTOR 2 = 256 Pages

270,336 bytes (256K + 8K)

SECTOR 3 = 256 Pages

270,336 bytes (256K + 8K)

SECTOR 31 = 256 Pages

270,336 bytes (256K + 8K)

SECTOR 0

SECTOR 1

SECTOR 2

BLOCK 0

BLOCK 1

BLOCK 2

BLOCK 30

BLOCK 31

BLOCK 32

BLOCK 33

BLOCK 62

BLOCK 63

BLOCK 64

BLOCK 65

8 Pages

BLOCK 0

BLOCK 1

PAGE 0

PAGE 1

PAGE 6

PAGE 7

PAGE 8

PAGE 9

PAGE 14

PAGE 15

PAGE 16

PAGE 17

PAGE 18

SECTOR 32 = 256 Pages

270,336 bytes (256K + 8K)

Device Operation

BLOCK 1022

BLOCK 1023

Block = 8448 bytes

(8K + 256)

The device operation is controlled by instructions from the host processor. The list of instructions and their associated opcodes are contained in Tables 1 through 4. A valid instruction starts with the falling edge of CS buffer or main memory address location. While the CS

followed by the appropriate 8-bit opcode and the desired

pin is low, toggling the SCK/CLK pin

PAGE 8189

PAGE 8190

PAGE 8191

Page = 1056 bytes

(1K + 32)

controls the loading of the opcode and the desired buffer or main memory address location through either the SI (serial input) pin or the parallel input pins (I/O7 - I/O0). All instructions, addresses, and data are transferred with the most significant bit (MSB) first.

Buffer addressing is referenced in the datasheet using the terminology BFA10 - BFA0 to denote the 11 address bits required to designate a byte address within a buffer. Main memory addressing is referenced using the terminology PA12 - PA0 and BA10 - BA0, where PA12 -

PA0 denotes the 13 address bits required to designate a page address and BA10 - BA0

denotes the 11 address bits required to designate a byte address within the page.

Read Commands By specifying the appropriate opcode, data can be read from the main memory or from either

one of the two SRAM data buffers. The DataFlash supports two categories of read modes in relation to the SCK/CLK signal. The differences between the modes are in respect to the inactive state of the SCK/CLK signal as well as which clock cycle data will begin to be output. The two categories, which are comprised of four modes total, are defined as Inactive Clock Polarity Low or Inactive Clock Polarity High and SPI Mode 0 or SPI Mode 3. A separate opcode (refer to Table 1 for a complete list) is used to select which category will be used for reading. Please refer to the “Detailed Bit-level Read Timing” diagrams in this datasheet for details on the clock cycle sequences for each mode.

1638F–DFLSH–09/02

CONTINUOUS ARRAY READ: By supplying an initial starting address for the main memory

array, the Continuous Array Read command can be utilized to sequentially read a continuous stream of data from the device by simply providing a clock signal; no additional addressing information or control signals need to be provided. The DataFlash incorporates an internal address counter that will automatically increment on every clock cycle, allowing one continuous read operation without the need of additional address sequences. To perform a continuous read, an opcode of 68H or E8H must be clocked into the device followed by three address bytes (which comprise the 24-bit page and byte address sequence) and a series of don’t care bytes (four don’t care bytes if using the serial interface or 60 don’t care bytes if using the parallel interface). The first 13 bits (PA12 - PA0) of the 24-bit (three byte) address sequence specify which page of the main memory array to read, and the last 11 bits (BA10 -

BA0) of the 24-bit address sequence specify the starting byte address within the page. The four or 60 don’t care bytes that follow the three address bytes are needed to initialize the read operation. Following the don’t care bytes, additional clock pulses on the SCK/CLK pin will result in data being output on either the SO (serial output) pin or the parallel output pins (I/O7I/O0).

The CS care bytes, and the reading of data. When the end of a page in main memory is reached during a Continuous Array Read, the device will continue reading at the beginning of the next page with no delays incurred during the page boundary crossover (the crossover from the end of one page to the beginning of the next page). When the last bit (or byte if using the parallel interface mode) in the main memory array has been read, the device will continue reading back at the beginning of the first page of memory. As with crossing over page boundaries, no delays will be incurred when wrapping around from the end of the array to the beginning of the array.

A low-to-high transition on the CS pins (SO or I/O7-I/O0). The maximum SCK/CLK frequency allowable for the Continuous Array Read is defined by the f buffers and leaves the contents of the buffers unchanged.

BURST ARRAY READ WITH SYNCHRONOUS DELAY: The Burst Array Read with Synchronous Delay functions very similarly to the Continuous Array Read operation but allows much higher read throughputs by utilizing faster clock frequencies. It incorporates a synchronous delay (through the use of don't care clock cycles) when crossing over page boundaries. To perform a Burst Array Read with Synchronous Delay, an opcode of 69H or E9H must be clocked into the device followed by three address bytes (which comprise the 24-bit page and byte address sequence) and a series of don't care bytes (four don't care bytes if using the serial interface or 60 don't care bytes if using the parallel interface). The first 13 bits (PA12PA0) of the 24-bit (three byte) address sequence specify which page of the main memory array to read, and the last 11 bits (BA10-BA0) of the 24-bit address sequence specify the starting byte address within the page. The don't care bytes that follow the three address bytes are needed to initialize the read operation. Following the don't care bytes, additional clock pulses on the SCK/CLK pin will result in data being output on either the SO pin or the I/O7-I/O0 pins.

pin must remain low during the loading of the opcode, the address bytes, the don’t

pin will terminate the read operation and tri-state the output

specification. The Continuous Array Read bypasses both data

CAR

AT45DB642

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AT45DB642

As with the Continuous Array Read, the CS pin must remain low during the loading of the opcode, the address bytes, the don't care bytes, and the reading of data. During a Burst Array Read with Synchronous Delay, when the end of a page in main memory is reached (the last bit or the last byte of the page has been clocked out), the system must send an additional 32 don't care clock cycles before the first bit (or byte if using the parallel interface mode) of the next page can be read out. These 32 don't care clock cycles are necessary to allow the device enough time to cross over the burst read boundary (the crossover from the end of one page to the beginning of the next page). By utilizing the 32 don't care clock cycles, the system does not need to delay the SCK/CLK signal to the device which allows synchronous operation when reading multiple pages of the memory array. Please see the detailed read timing waveforms for illustrations (beginning on page 21) on which clock cycle data will actually begin to be output.

When the last bit (or byte in the parallel interface mode) in the main memory array has been read, the device will continue reading back at the beginning of the first page of memory. The transition from the last bit (or byte when using the parallel interface) of the array back to the beginning of the array is also considered a burst read boundary. Therefore, the system must send 32 don't care clock cycles before the first bit (or byte if using the parallel interface mode) of the memory array can be read.

A low-to-high transition on the CS pins (SO or I/O7-I/O0). The maximum SCK/CLK frequency allowable for the Burst Array Read with Synchronous Delay is defined by the f chronous Delay bypasses both data buffers and leaves the contents of the buffers unchanged.

MAIN MEMORY PAGE READ: A main memory page read allows the user to read data directly from any one of the 8192 pages in the main memory, bypassing both of the data buffers and leaving the contents of the buffers unchanged. To start a page read, an opcode of 52H or D2H must be clocked into the device followed by three address bytes (which comprise the 24-bit page and byte address sequence) and a series of don’t care bytes (four don’tcarebytes if using the serial interface or 60 don’t care bytes if the using parallel interface). The first 13 bits (PA12 - PA0) of the 24-bit (three-byte) address sequence specify the page in main memory to be read, and the last 11 bits (BA10 - BA0) of the 24-bit address sequence specify the starting byte address within that page. The four or 60 don’t care bytes that follow the three address bytes are sent to initialize the read operation. Following the don’tcarebytes,additional pulses on SCK/CLK result in data being output on either the SO (serial output) pin or the parallel output pins (I/O7 - I/O0). The CS opcode, the address bytes, the don’t care bytes, and the reading of data. When the end of a page in main memory is reached, the device will continue reading back at the beginning of the same page. A low-to-high transition on the CS state the output pins (SO or I/O7 - I/O0).

BUFFER READ: Data can be read from either one of the two buffers, using different opcodes to specify which buffer to read from. An opcode of 54H or D4H is used to read data from buffer 1, and an opcode of 56H or D6H is used to read data from buffer 2. To perform a buffer read, the opcode must be clocked into the device followed by three address bytes comprised of 13 don’t care bits and 11 buffer address bits (BFA10 - BFA0). Following the three address bytes, an additional don’t care byte must be clocked in to initialize the read operation. Since the buffer size is 1056 bytes, 11 buffer address bits are required to specify the first byte of data to be read from the buffer. The CS address bytes, the don’t care bytes, and the reading of data. When the end of a buffer is reached, the device will continue reading back at the beginning of the buffer. A low-to-high transition on the CS I/O7 - I/O0).

pin will terminate the read operation and tri-state the output pins (SO or

pin will terminate the read operation and tri-state the output

specification. The Burst Array Read with Syn-

BARSD

pin must remain low during the loading of the

pin will terminate the read operation and tri-

pin must remain low during the loading of the opcode, the

1638F–DFLSH–09/02

STATUS REGISTER READ: The status register can be used to determine the device’s

ready/busy status, the result of a Main Memory Page to Buffer Compare operation, or the device density. To read the status register, an opcode of 57H or D7H must be loaded into the device. After the opcode is clocked in, the 1-byte status register will be clocked out on the output pins (SO or I/O7 - I/O0), starting with the next clock cycle. When using the serial interface, the data in the status register, starting with the MSB (bit 7), will be clocked out on the SO pin during the next eight clock cycles.

The five most-significant bits of the status register will contain device information, while the remaining three least-significant bits are reserved for future use and will have undefined values. After the one byte of the status register has been clocked out, the sequence will repeat itself (as long as CS ter is constantly updated, so each repeating sequence will output new data.

Ready/busy status is indicated using bit 7 of the status register. If bit 7 is a 1, then the device is not busy and is ready to accept the next command. If bit 7 is a 0, then the device is in a busy state. The user can continuously poll bit 7 of the status register by stopping SCK/CLK at a low level once bit 7 has been output on the SO or I/O7 pin. The status of bit 7 will continue to be output on the SO or I/O7 pin, and once the device is no longer busy, the state of the SO or I/O7 pin will change from 0 to 1. There are eight operations that can cause the device to be in a busy state: Main Memory Page to Buffer Transfer, Main Memory Page to Buffer Compare, Buffer to Main Memory Page Program with Built-in Erase, Buffer to Main Memory Page Program without Built-in Erase, Page Erase, Block Erase, Main Memory Page Program, and Auto Page Rewrite.

The result of the most recent Main Memory Page to Buffer Compare operation is indicated using bit 6 of the status register. If bit 6 is a 0, then the data in the main memory page matches the data in the buffer. If bit 6 is a 1, then at least one bit of the data in the main memory page does not match the data in the buffer.

remains low and SCK/CLK is being toggled). The data in the status regis-

Program and Erase Commands

The device density is indicated using bits 5, 4, 3 and 2 of the status register. For the AT45DB642, the four bits are logical “1”s. The decimal value of these four binary bits does not equate to the device density; the four bits represent a combinational code relating to differing densities of DataFlash devices, allowing a total of sixteen different density configurations.

Status Register Format

Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0

RDY/BUSY

BUFFER WRITE: Data can be clocked in from the input pins (SI or I/O7 - I/O0) into either buffer 1 or buffer 2. To load data into either buffer, a 1-byte opcode, 84H for buffer 1 or 87H for buffer 2, must be clocked into the device, followed by three address bytes comprised of 13 don’t care bits and 11 buffer address bits (BFA10 - BFA0). The 11 buffer address bits specify the first byte in the buffer to be written. After the last address byte has been clocked into the device, data can then be clocked in on subsequent clock cycles. If the end of the data buffer is reached, the device will wrap around back to the beginning of the buffer. Data will continue to be loaded into the buffer until a low-to-high transition is detected on the CS

COMP1111XX

pin.

AT45DB642

1638F–DFLSH–09/02

AT45DB642

BUFFER TO MAIN MEMORY PAGE PROGRAM WITH BUILT-IN ERASE: Data written into

either buffer 1 or buffer 2 can be programmed into the main memory. A 1-byte opcode, 83H for buffer 1 or 86H for buffer 2, must be clocked into the device followed by three address bytes consisting of 13 page address bits (PA12 - PA0) that specify the page in the main memory to be written and 11 don’t care bits. When a low-to-high transition occurs on the CS will first erase the selected page in main memory (the erased state is a logical 1) and then program the data stored in the buffer into the specified page in main memory. Both the erase and the programming of the page are internally self-timed and should take place in a maximum time of t

. During this time, the status register and the RDY/BUSY pin will indicate that the

part is busy.

BUFFER TO MAIN MEMORY PAGE PROGRAM WITHOUT BUILT-IN ERASE: A previouslyerased page within main memory can be programmed with the contents of either buffer 1 or buffer 2. A 1-byte opcode, 88H for buffer 1 or 89H for buffer 2, must be clocked into the device followed by three address bytes consisting of 13 page address bits (PA12 - PA0) that specify the page in the main memory to be written and 11 don’t care bits. When a low-to-high transition occurs on the CS

pin, the part will program the data stored in the buffer into the specified page in the main memory. It is necessary that the page in main memory that is being programmed has been previously erased using one of the optional erase commands (Page Erase or Block Erase). The programming of the page is internally self-timed and should take place in a maximum time of t

. During this time, the status register and the RDY/BUSY pin will indicate

that the part is busy.

pin, the part

Successive page programming operations, without doing a page erase, are not recommended. In other words, changing bytes within a page from a “1” to a “0” during multiple page programming operations without erasing that page is not recommended.

PAGE ERASE: The optional Page Erase command can be used to individually erase any page in the main memory array allowing the Buffer to Main Memory Page Program without Built-in Erase command to be utilized at a later time. To perform a page erase, an opcode of 81H must be loaded into the device, followed by three address bytes comprised of 13 page address bits (PA12 - PA0) and 11 don’t care bits. The 13 page address bits are used to specify which page of the memory array is to be erased. When a low-to-high transition occurs on the CS operation is internally self-timed and should take place in a maximum time of t time, the status register and the RDY/BUSY

pin, the part will erase the selected page (the erased state is a logical 1). The erase

. During this

pin will indicate that the part is busy.

BLOCK ERASE: A block of eight pages can be erased at one time allowing the Buffer to Main Memory Page Program without Built-in Erase command to be utilized to reduce programming times when writing large amounts of data to the device. To perform a block erase, an opcode of 50H must be loaded into the device, followed by three address bytes comprised of 10 page address bits (PA12 -PA3) and 14 don’t care bits. The 10 page address bits are used to specify which block of eight pages is to be erased. When a low-to-high transition occurs on the CS pin, the part will erase the selected block of eight pages. The erase operation is internally selftimed and should take place in a maximum time of t the RDY/BUSY

pin will indicate that the part is busy.

. During this time, the status register and

1638F–DFLSH–09/02

Block Erase Addressing

PA12 PA11 PA10 PA9 PA8 PA7 PA6 PA5 PA4 PA3 PA2 PA1 PA0 Block

0 0 0 0000000XXX 0

0 0 0 0000001XXX 1

0 0 0 0000010XXX 2

0 0 0 0000011XXX 3

•

1 1 1 1111100XXX1020

1 1 1 1111101XXX1021

1 1 1 1111110XXX1022

1 1 1 1111111XXX1023

•

MAIN MEMORY PAGE PROGRAM THROUGH BUFFER: This operation is a combination of the Buffer Write and Buffer to Main Memory Page Program with Built-in Erase operations. Data is first clocked into buffer 1 or buffer 2 from the input pins (SI or I/O7 - I/O0) and then programmed into a specified page in the main memory. A 1-byte opcode, 82H for buffer 1 or 85H for buffer 2, must first be clocked into the device, followed by three address bytes. The address bytes are comprised of 13 page address bits (PA12 - PA0) that select the page in the main memory where data is to be written, and 11 buffer address bits (BFA10 - BFA0) that select the first byte in the buffer to be written. After all address bytes are clocked in, the part will take data from the input pins and store it in the specified data buffer. If the end of the buffer is reached, the device will wrap around back to the beginning of the buffer. When there is a low-to-high transition on the CS

pin, the part will first erase the selected page in main memory to all 1s and then program the data stored in the buffer into that memory page. Both the erase and the programming of the page are internally self-timed and should take place in a maximum time of t

. During this time, the status register and the RDY/BUSY pin will indicate that

the part is busy.

•

Additional Commands

AT45DB642

MAIN MEMORY PAGE TO BUFFER TRANSFER: A page of data can be transferred from the

main memory to either buffer 1 or buffer 2. To start the operation, a 1-byte opcode, 53H for buffer 1 and 55H for buffer 2, must be clocked into the device, followed by three address bytes comprised of 13 page address bits (PA12 - PA0), which specify the page in main memory that is to be transferred, and 11 don’tcarebits.TheCS

pin must be low while toggling the SCK/CLK pin to load the opcode and the address bytes from the input pins (SI or I/O7 - I/O0). The transfer of the page of data from the main memory to the buffer will begin when the CS transitions from a low to a high state. During the transfer of a page of data (t register can be read or the RDY/BUSY

can be monitored to determine whether the transfer

), the status

XFR

has been completed.

1638F–DFLSH–09/02

AT45DB642

MAIN MEMORY PAGE TO BUFFER COMPARE: A page of data in main memory can be

compared to the data in buffer 1 or buffer 2. To initiate the operation, a 1-byte opcode, 60H for buffer 1 and 61H for buffer 2, must be clocked into the device, followed by three address bytes consisting of 13 page address bits (PA12 - PA0) that specify the page in the main memory that is to be compared to the buffer, and 11 don’tcarebits.TheCS the SCK/CLK pin to load the opcode and the address bytes from the input pins (SI or I/O7 -

I/O0). On the low-to-high transition of the CS page will be compared with the 1056 bytes in buffer 1 or buffer 2. During this time (t status register and the RDY/BUSY compare operation, bit 6 of the status register is updated with the result of the compare.

AUTO PAGE REWRITE: This mode is only needed if multiple bytes within a page or multiple pages of data are modified in a random fashion. This mode is a combination of two operations: Main Memory Page to Buffer Transfer and Buffer to Main Memory Page Program with Built-in Erase. A page of data is first transferred from the main memory to buffer 1 or buffer 2, and then the same data (from buffer 1 or buffer 2) is programmed back into its original page of main memory. To start the rewrite operation, a 1-byte opcode, 58H for buffer 1 or 59H for buffer 2, must be clocked into the device, followed by three address bytes comprised of 13 page address bits (PA12 - PA0) that specify the page in main memory to be rewritten and 11 don’t care bits. When a low-to-high transition occurs on the CS data from the page in main memory to a buffer and then program the data from the buffer back into same page of main memory. The operation is internally self-timed and should take place in a maximum time of t cate that the part is busy.

. During this time, the status register and the RDY/BUSY pin will indi-

pin will indicate that the part is busy. On completion of the

pin, the 1056 bytes in the selected main memory

pin must be low while toggling

), the

XFR

pin, the part will first transfer

Operation Mode Summary

If a sector is programmed or reprogrammed sequentially page by page, then the programming algorithm shown in Figure 1 (page 33) is recommended. Otherwise, if multiple bytes in a page or several pages are programmed randomly in a sector, then the programming algorithm shown in Figure 2 (page 34) is recommended. Each page within a sector must be updated/rewritten at least once within every 10,000 cumulative page erase/program operations in that sector.

The modes described can be separated into two groups – modes that make use of the Flash memory array (Group A) and modes that do not make use of the Flash memory array (Group B).

Group A modes consist of:

1. Main Memory Page to Buffer 1 (or 2) Transfer

2. Main Memory Page to Buffer 1 (or 2) Compare

3. Buffer 1 (or 2) to Main Memory Page Program with Built-in Erase

4. Buffer 1 (or 2) to Main Memory Page Program without Built-in Erase

5. Page Erase

6. Block Erase

7. Main Memory Page Program through Buffer

8. Auto Page Rewrite

9. Group B modes consist of:

10. Buffer 1 (or 2) Read

11. Buffer 1 (or 2) Write

12. Status Register Read

1638F–DFLSH–09/02

If a Group A mode is in progress (not fully completed), then another mode in Group A should not be started. However, during this time in which a Group A mode is in progress, modes in Group B can be started.

This gives the DataFlash the ability to virtually accommodate a continuous data stream. While data is being programmed into main memory from buffer 1, data can be loaded into buffer 2 (or vice versa). See application note AN-4 (“Using Atmel’s Serial DataFlash”) for more details.

Pin Descriptions SERIAL/PARALLEL INTERFACE CONTROL (SER/PAR): The DataFlash may be configured

to utilize either its serial port or parallel port through the use of the serial/parallel control pin (SER/PAR and parallel modes offered on the same device. When the SER/PAR port (SI and SO) of the DataFlash will be used for all data transfers, and the parallel port (I/O7 - I/O0) will be in a high impedance state. Any data presented on the parallel port while SER/PAR used for all data transfers, and the SO pin of the serial port will be in a high impedance state. While SER/PAR the serial port and parallel port can be done at anytime provided the following conditions are met: 1) CS (SER/PAR hold time) and T

Having both a serial port and a parallel port on the DataFlash allows the device to reside on two buses that can be connected to different processors. The advantage of switching between the serial and parallel port is that while an internally self-timed operation such as an erase or program operation is started with either port, a simultaneous operation such as a buffer read or buffer write can be started utilizing the other port.

). The Dual Interface offers more flexibility in a system design with both the serial

pin is held high, the serial

is held high will be ignored. When the SER/PAR is held low, the parallel port will be

is low, any data presented on the SI pin will be ignored. Switching between

should be held high during the switching between the two modes. 2) T

(SER/PAR Setup time) requirements should be followed.

SPS

SPH

The SER/PAR then connection of the SER/PAR connected or if the SER/PAR pins (I/O7-I/O0), the VCCP pin, and the GNDP pin should be treated as “don’t connects.”

SERIAL INPUT (SI): The SI pin is an input-only pin and is used to shift data serially into the device. The SI pin is used for all data input, including opcodes and address sequences. If the SER/PAR

SERIAL OUTPUT (SO): The SO pin is an output-only pin and is used to shift data serially out from the device. If the SER/PAR connect”.

PARALLEL INPUT/OUTPUT (I/O7-I/O0): The I/O7-I/O0 pins are bidirectional and used to clock data into and out of the device. The I/O7-I/O0 pins are used for all data input, including opcodes and address sequences. The use of these pins is optional, and the pins should be treated as “don’t connects” if the SER/PAR always driven high externally.

SERIAL CLOCK/CLOCK (SCK/CLK): The SCK/CLK pin is an input-only pin and is used to control the flow of data to and from the DataFlash. Data is always clocked into the device on the rising edge of SCK/CLK and clocked out of the device on the falling edge of SCK/CLK.

CHIP SELECT (CS

not selected, data will not be accepted on the input pins (SI or I/O7-I/O0), and the output pins (SO or I/O7-I/O0) will remain in a high impedance state. A high-to-low transition on the CS is required to start an operation, and a low-to-high transition on the CS an operation.

pin is internally pulled high; therefore, if the parallel port is never to be used,

pin is not necessary. In addition, if the SER/PAR pin is not

pin is always driven high externally, then the parallel input/output

pin is always driven low, then the SI pin should be a “don’t connect”.

pin is always driven low, then the SO pin should be a “don’t

pin is not connected or if the SER/PAR pin is

): The DataFlash is selected when the CS pin is low. When the device is

pinisrequiredtoend

HARDWARE PAGE WRITE PROTECT: If the WP

0 and 1) of the main memory cannot be reprogrammed. The only way to reprogram the first 256 pages is to first drive the protect pin high and then use the program commands previously mentioned. The WP nection of the WP recommended that the WP

AT45DB642

pin is held low, the first 256 pages (sectors

pin is internally pulled high; therefore, in low pin count applications, con-

pin is not necessary if this pin and feature will not be utilized. However, it is

pin be driven high externally whenever possible.

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AT45DB642

RESET: Alowstateontheresetpin(RESET) will terminate the operation in progress and

reset the internal state machine to an idle state. The device will remain in the reset condition as long as a low level is present on the RESET RESET

The device incorporates an internal power-on reset circuit, so there are no restrictions on the RESET fore, in low pin count applications, connection of the RESET feature will not be utilized. However, it is recommended that the RESET externally whenever possible.

pin is brought back to a high level.

pin during power-on sequences. The RESET pin is also internally pulled high; there-

pin. Normal operation can resume once the

pin is not necessary if this pin and

pinbedrivenhigh

Power-on/Reset State

System Considerations

READY/BUSY

internally self-timed operation. This pin, which is normally in a high state (through an external pull-up resistor), will be pulled low during programming/erase operations, compare operations, and page-to-buffer transfers.

The busy status indicates that the Flash memory array and one of the buffers cannot be accessed; read and write operations to the other buffer can still be performed.

PARALLEL PORT SUPPLY VOLTAGE (VCCP AND GNDP): The VCCP and GNDP pins are used to supply power for the parallel input/output pins (I/O7-I/O0). The VCCP and GNDP pins need to be used if the parallel port is to be utilized; however, these pins should be treated as “don’t connects” if the SER/PAR high externally.

When power is first applied to the device, or when recovering from a reset condition, the device will default to SPI Mode 3 or Inactive Clock Polarity High. In addition, the output pins (SO or I/O7 - I/O0) will be in a high impedance state, and a high-to-low transition on the CS will be required to start a valid instruction. The SPI mode or the clock polarity mode will be automatically selected on every falling edge of CS

The SPI interface is controlled by the serial clock SCK, serial input SI and chip select CS pins. The sequential 8-bit parallel interface is controlled by the clock CLK, 8 I/Os and chip select CS pins. These signals must rise and fall monotonically and be free from noise. Excessive noise or ringing on these pins can be misinterpreted as multiple edges and cause improper operation of the device. The PC board traces must be kept to a minimum distance or appropriately terminated to ensure proper operation. If necessary, decoupling capacitors can be added on these pins to provide filtering against noise glitches.

: This open drain output pin will be driven low when the device is busy in an

pin is not connected or if the SER/PAR pin is always driven

by sampling the inactive Clock State.

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As system complexity continues to increase, voltage regulation is becoming more important. A key element of any voltage regulation scheme is its current sourcing capability. Like all Flash memories, the peak current for DataFlash occur during the programming and erase operation. The regulator needs to supply this peak current requirement. An under specified regulator can cause current starvation. Besides increasing system noise, current starvation during programming or erase can lead to improper operation and possible data corruption.

Table 1 . Read Commands

Command SCK/CLK Mode Opcode

Continuous Array Read

Burst Array Read with Synchronous Delay

Main Memory Page Read

Buffer 1 Read

Buffer 2 Read

Status Register Read

Inactive Clock Polarity Low or High 68H

SPI Mode 0 or 3 E8H

Inactive Clock Polarity Low or High 69H

SPI Mode 0 or 3 E9H

Inactive Clock Polarity Low or High 52H

SPI Mode 0 or 3 D2H

Inactive Clock Polarity Low or High 54H

SPI Mode 0 or 3 D4H

Inactive Clock Polarity Low or High 56H

SPI Mode 0 or 3 D6H

Inactive Clock Polarity Low or High 57H

SPI Mode 0 or 3 D7H

Table 2 . Program and Erase Commands

Command SCK/CLK Mode Opcode

Buffer 1 Write Any 84H

Buffer 2 Write Any 87H

Buffer 1 to Main Memor y Page Program with Built-in Erase Any 83H

Buffer 2 to Main Memor y Page Program with Built-in Erase Any 86H

Buffer 1 to Main Memor y Page Program without Built-in Erase Any 88H

Buffer 2 to Main Memor y Page Program without Built-in Erase Any 89H

Page Erase Any 81H

Block Erase Any 50H

Main Memory Page Program Through Buffer 1 Any 82H

Main Memory Page Program Through Buffer 2 Any 85H

Table 3 . Additional Commands

Command SCK/CLK Mode Opcode

Main Memory Page to Buffer 1 Transfer Any 53H

Main Memory Page to Buffer 2 Transfer Any 55H

Main Memory Page to Buffer 1 Compare Any 60H

Main Memory Page to Buffer 2 Compare Any 61H

Auto Page Rewrite Through Buffer 1 Any 58H

Auto Page Rewrite Through Buffer 2 Any 59H

Note: In Tables 2 and 3, an SCK/CLK mode designation of “Any” denotes any one of the four modes of operation (Inactive Clock

Polarity Low, Inactive Clock Polarity High, SPI Mode 0, or SPI Mode 3).

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