Datasheet

Flash memory is a non-volatile storage chip that
can be electrically erased and reprogrammed. It
was developed from EEPROM (electrically erasable
programmable read-only memory) and must be
erased in fairly large blocks before these can be
rewritten with new data. The high density NAND
type must also be programmed and read in (smaller)
blocks, or pages, while the NOR type allows a single
machine word (byte) to be written or read independently.
Flash memories come in dierent sizes and supporting
dierent clock speeds. They are mostly used for mass
storage, as in USB Flash Drives, which are very popular today.
EasyMx PRO
™
v7 features M25P80 Serial Flash Memory which uses
SPI communication interface and has 8 Mbits of available memory,
organized as 16 sectors, each containing 256 pages. Each page is 256 bytes
wide. Thus, the whole memory can be viewed as consisting of 4096 pages, or
1,048,576 bytes. Maximum clock frequency for READ instructions is 40MHz.
other modules
page 36
Serial Flash Memory
In order to connect Serial Flash Memory
to the microcontroller you must enable
SW13.1, SW13.2, SW13.3 and SW13.8
switches. This connects SPI lines to MCU_
MOSI, MCU_MISO, MCU_SCK and PD7 (CS)
microcontroller pins.
The Serial Peripheral Interface Bus or SPI bus is a synchronous serial data link standard that operates in full
duplex mode. It consists of four lines MISO (Master Input Slave Output), MOSI (Master Output Slave Input), SCK
(Clock) and CS (Chip Select). Devices communicate in master/slave mode where the master device initiates the
data frame. Multiple slave devices are allowed with individual slave select (chip select) lines.
Enabling Serial Flash
What is SPI?
Figure 22-1:
Schematic of
Serial Flash
Memory module
EasyMx PRO
v7
1
2
3
54
6
7
8
CS
SDO
WP
GND SDI
SCK
HOLD
VCC
U6
25P80
VCC-3.3V
R39
100K
C27
100nF
VCC-3.3V
FLASH-CS#
PH_MISO
PH_MOSI
PH_SCK
R43 27
VCC-3.3V
1 2 3 4 5 6 7 8
O
N
SW13
FLASH-CS#
PH_MOSI
PH_MISO
PH_SCK
PD7
MCU_MOSI
MCU_SCK
MCU_MISO
DATA BUS