EN25QH256 Datasheet, PDF (36/74 Pages) Eon Silicon Solution Inc. – 256 Megabit Serial Flash Memory with 4Kbyte Uniform Sector

EN25QH256
Read Data Bytes (READ) (03h)
The device is first selected by driving Chip Select (CS#) Low. The instruction code for the Read Data
Bytes (READ) instruction is followed by a 3-byte or 4-byte address (depending on mode state), each bit
being latched-in during the rising edge of Serial Clock (CLK). Then the memory contents, at that
address, is shifted out on Serial Data Output (DO), each bit being shifted out, at a maximum frequency
fR, during the falling edge of Serial Clock (CLK).
The instruction sequence is shown in Figure 16. The first byte addresses can be at any location. To
access higher address (larger than 128Mb), there are two methods. One is the Enter 4-byte mode (B7h)
command and the other is the Enter High Bank Latch Mode (67h) command. For these methods, the
address is automatically incremented to the next higher address after each byte of data is shifted out.
The whole memory can, therefore, be read with a single Read Data Bytes (READ) instruction. When
the highest address is reached, the address counter rolls over to 000000h, allowing the read sequence
to be continued indefinitely.
The default read mode is 3-byte address, to access higher address (4-byte address) which requires to
enter the 4-byte address read mode. To enter the 4-byte mode, please refer to the enter 4-byte mode
(EN4B) Mode section.
The Read Data Bytes (READ) instruction is terminated by driving Chip Select (CS#) High. Chip Select
(CS#) can be driven High at any time during data output. Any Read Data Bytes (READ) instruction,
while an Erase, Program or Write cycle is in progress, is rejected without having any effects on the
cycle that is in progress.
Figure 16. Read Data Instruction Sequence Diagram
Note: Please note the above address cycles are base on 3-byte address mode, for 4-byte address
mode, the address cycles will be increased.
This Data Sheet may be revised by subsequent versions
36
or modifications due to changes in technical specifications.
©2004 Eon Silicon Solution, Inc.,
Rev. E, Issue Date: 2012/01/30
www.eonssi.com