Article ID: 000081655 Content Type: Product Information & Documentation Last Reviewed: 09/11/2012

How should data be written to the serial configuration (EPCS) devices when using the ALTASMI_PARALLEL megafunction?

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Description

When writing data to serial configuration (EPCS) devices using the ALTASMI_PARALLEL megafunction, the EPCS devices only allow you to change the bits in the memory from 1 to 0. However they do not allow you to change the bits in the memory from 0 to 1.

 

For example, if the initial data in a certain address is 0xE8 and you try to write a data byte 0x7A in the same address using the write bytes operation, the data becomes 0x68 since the bit1 and bit4 of the initial data byte 0xE8 cannot be changed from 0 to 1.

 

In order to change bits from 0 to 1, you have to erase the targeted sector memory or erase all memory in the serial configuration device. The bytes of serial configuration devices memory must be erased to all 1 or 0xFF before write bytes operation is implemented.

 

Therefore when using the altasmi_parallel, you need to use either the erase sector instruction to erase in a sector, or the erase bulk instruction to erase throughout the entire memory before write operation (single-byte write or page-write operation).

 

This will ensure the serial configuration (EPCS) device is correctly written with new data.

Related Products

This article applies to 2 products

Intel® Programmable Devices
Intel® FPGA Configuration Devices