Quad-Serial Configuration (EPCQ) Devices Datasheet

ID 683078
Date 1/23/2020
Document Table of Contents

1.7.4. Read Bytes Operation (03h)

When you execute the read bytes operation, you first shift in the read bytes operation code, followed by a 3-byte addressing mode (A[23..0]) or a 4-byte addressing mode (A[31..0]). Each address bit must be latched in on the rising edge of the DCLK signal. After the address is latched in, the memory contents of the specified address are shifted out serially on the DATA1 pin, beginning with the MSB. For reading Raw Programming Data File (.rpd), the content is shifted out serially beginning with the LSB. Each data bit is shifted out on the falling edge of the DCLK signal. The maximum DCLK frequency during the read bytes operation is 50 MHz.

Figure 10. Read Bytes Operation Timing DiagramTo access the entire EPCQ256 or EPCQ512/A memory, use 4-byte addressing mode. In the 4-byte addressing mode, the address width is 32-bit address.

The first byte address can be at any location. The device automatically increases the address to the next higher address after shifting out each byte of data. Therefore, the device can read the whole memory with a single read bytes operation. When the device reaches the highest address, the address counter restarts at 0x000000, allowing the memory contents to be read out indefinitely until the read bytes operation is terminated by driving the nCS signal high. If the read bytes operation is shifted in while a write or erase cycle is in progress, the operation is not executed and does not affect the write or erase cycle in progress.