EPCQ16SI8N View Datasheet(PDF) - Altera Corporation

Part Name

Description

Manufacturer

EPCQ16SI8N

Quad-Serial Configuration (EPCQ) Devices

Altera Corporation 

Memory Operations

Page 11

Memory Operations

This section describes the operations that you can use to access the memory in EPCQ

devices. When performing the operation, addresses and data are shifted in and out of

the device serially, with the MSB first.

Timing Requirements

When the active low chip select (nCS) signal is driven low, shift in the operation code

into the EPCQ device using the serial data (DATA) pin. Each operation code bit is

latched into the EPCQ device on the rising edge of the DCLK.

While executing an operation, shift in the desired operation code, followed by the

address or data bytes as listed in Table 8. The device must drive the nCS pin high after

the last bit of the operation sequence is shifted in.

For read operations, the data read is shifted out on the DATA pin. You can drive the nCS

pin high when any bit of the data is shifted out.

For write and erase operations, drive the nCS pin high at a byte boundary, that is in a

multiple of eight clock pulses. Otherwise, the operation is rejected and not executed.

All attempts to access the memory contents while a write or erase cycle is in progress

are rejected, and the write or erase cycle continues unaffected.

Addressing Mode

The 3-byte addressing mode is enabled by default. To access the EPCQ256 memory,

you must use the 4-byte addressing mode. In 4-byte addressing mode, the address

width is 32-bit address. To enable the 4-byte addressing mode, you must execute the

4BYTEADDREN operation. This addressing mode takes effect immediately after you

execute the 4BYTEADDREN operation and remains active in the subsequent

power-ups. To disable the 4-byte addressing mode, you must execute the

4BYTEADDREX operation.

1 If you are using the Quartus II software or the SRunner software to program the

EPCQ256 device, you do not need to execute the 4BYTEADDREN operation. These

software automatically enable the 4-byte addressing mode when programming the

device.

July 2012 Altera Corporation

Quad-Serial Configuration (EPCQ) Devices Datasheet

Share Link: