Features
• Single 4.5V - 5.5V Supply
• Serial Interface Architecture
• Page Program Operation
– Single Cycle Reprogram (Erase and Program)
– 1024 Pages (264 Bytes/Page) Main Memory
• Two 264-Byte SRAM Data Buffers – Allows Receiving of Data
while Reprogramming of Nonvolatile Memory
• Internal Program and Control Timer
• Fast Page Program Time – 7 ms Typical
• 80 µs Typical Page to Buffer Transfer Time
• Low Power Dissipation
– 15 mA Active Read Current Typical
– 15 µA CMOS Standby Current Typical
• 10 MHz Max Clock Frequency
• Hardware Data Protection Feature
2-Megabit
5-volt Only
Serial
DataFlash®
• Serial Peripheral Interface (SPI) Compatible – Modes 0 and 3
• CMOS and TTL Compatible Inputs and Outputs
• Commercial and Industrial Temperature Ranges
Description
AT45D021
The AT45D021 is a 5-volt only, serial interface Flash memory suitable for in-system
reprogramming. Its 2,162,688 bits of memory are organized as 1024 pages of 264-
bytes each. In addition to the main memory, the AT45D021 also contains two data
SRAM buffers of 264-bytes each. The buffers allow receiving of data while a page in
the main memory is being reprogrammed. Unlike conventional Flash memories that
are accessed randomly with multiple address lines and a parallel interface, the
DataFlash uses a serial interface to sequentially access its data. The simple serial
interface facilitates hardware layout, increases system reliability, minimizes switching
(continued)
PLCC
Pin Configurations
Pin Name
Function
CS
Chip Select
Serial Clock
Serial Input
Serial Output
SCK
SI
5
6
7
8
9
29 WP
28 RESET
27 RDY/BUSY
26 NC
SCK
SI
SO
NC
NC
25 NC
NC 10
NC 11
NC 12
NC 13
24 NC
SO
23 NC
22 NC
WP
Harware Page Write
Protect Pin
21 NC
RESET
Chip Reset
Note:
PLCC package pins 16 and 17
are DON’T CONNECT.
RDY/BUSY Ready/Busy
TSOP Top View
Type 1
PLCC
GND
NC
NC
CS
SCK
SI
1
28
27
26
25
24
23
22
21
20
19
18
17
16
15
VCC
NC
2
RDY/BUSY
RESET
WP
1
28
27
26
25
24
23
22
21
20
19
18
17
16
15
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
3
NC
2
4
WP
3
5
RESET
RDY/BUSY
NC
NC
4
6
NC
5
SO
NC
NC
NC
NC
NC
NC
NC
7
VCC
GND
NC
6
8
NC
7
9
NC
8
10
11
12
13
14
NC
NC
9
NC
NC
10
11
12
13
14
NC
CS
Rev. 0869B–07/98
NC
SCK
SI
NC
SO
1