7–20
Chapter 7: User Flash Memory in MAX V Devices
Software Support for UFM Block
No Erase
The no erase operation never erases the UFM contents. This method is recommended
when UFM does not require constant re-writing after its initial write of data. For
example, if the UFM data is to be initialized with data during manufacturing using
I2C, you may not require writing to the UFM again. In that case, you should use the no
erase option and save LE resources from being used to create erase logic.
Read Operation
The read operation is initiated in the same manner as the write operation except that
the R/W bit must be set to 1. Three different read operations are supported:
■
■
■
Current Address Read (Single Byte)
Random Address Read (Single byte)
Sequential Read (Multi-Byte)
After each UFM data has been read and transferred to the master, the UFM address
register is incremented for all single and multi-byte read operations.
Current Address Read
This read operation targets the current byte location pointed to by the UFM address
register. Figure 7–15 shows the current address read sequence.
Figure 7–15. Current Address Read Sequence
Slave Address
Data
S
A
P
R/W
‘1’ (read)
From Master to Slave
From Slave to Master
S – Start Condition
P – Stop Condition
A – Acknowledge
MAX V Device Handbook
January 2011 Altera Corporation
ALTERA [ ALTERA CORPORATION ]
