EN25QH16 Datasheet, PDF (8/62 Pages) Eon Silicon Solution Inc. – 16 Megabit Serial Flash Memory with 4Kbyte Uniform Sector

OPERATING FEATURES
EN25QH16
Standard SPI Modes
The EN25QH16 is accessed through a SPI compatible bus consisting of four signals: Serial Clock
(CLK), Chip Select (CS#), Serial Data Input (DI) and Serial Data Output (DO). Both SPI bus operation
Modes 0 (0,0) and 3 (1,1) are supported. The primary difference between Mode 0 and Mode 3, as
shown in Figure 3, concerns the normal state of the CLK signal when the SPI bus master is in standby
and data is not being transferred to the Serial Flash. For Mode 0 the CLK signal is normally low. For
Mode 3 the CLK signal is normally high. In either case data input on the DI pin is sampled on the rising
edge of the CLK. Data output on the DO pin is clocked out on the falling edge of CLK.
Figure 3. SPI Modes
Dual SPI Instruction
The EN25QH16 supports Dual SPI operation when using the “Dual Output Fast Read and Dual I/O
Fast Read “ (3Bh and BBh) instructions. These instructions allow data to be transferred to or from the
Serial Flash memory at two to three times the rate possible with the standard SPI. The Dual Read
instructions are ideal for quickly downloading code from Flash to RAM upon power-up (code-shadowing)
or for application that cache code-segments to RAM for execution. The Dual output feature simply
allows the SPI input pin to also serve as an output during this instruction. When using Dual SPI
instructions the DI and DO pins become bidirectional I/O pins; DQ₀ and DQ₁. All other operations use
the standard SPI interface with single output signal.
Quad SPI Instruction
The EN25QH16 supports Quad output operation when using the Quad I/O Fast Read (EBh).This
instruction allows data to be transferred to or from the Serial Flash memory at four to six times the rate
possible with the standard SPI. The Quad Read instruction offer a significant improvement in
continuous and random access transfer rates allowing fast code-shadowing to RAM or for application
that cache code-segments to RAM for execution. The EN25QH16 also supports full Quad Mode
function while using the Enable Quad Peripheral Interface mode (EQPI) (38h). When using Quad SPI
instruction the DI and DO pins become bidirectional I/O pins; DQ₀ and DQ_1, and the WP# and HOLD#
pins become DQ₂ and DQ₃ respectively.
This Data Sheet may be revised by subsequent versions
8
or modifications due to changes in technical specifications.
©2004 Eon Silicon Solution, Inc.,
Rev. H, Issue Date: 2012/01/30
www.eonssi.com