7–18
Chapter 7: User Flash Memory in MAX V Devices
Software Support for UFM Block
The ALTUFM_I2C megafunction supports four different erase operation methods
shown on page 4 of the ALTUFM MegaWizard Plug-In Manager:
■
■
■
■
Full Erase (Device Slave Address Triggered)
Sector Erase (Byte Address Triggered)
Sector Erase (A2 Triggered)
No Erase
These erase options only work as described if that particular option is selected in the
MegaWizard Plug-In Manager before compiling the design files and programming
the device. Only one option can be selected for the ALTUFM_I2C megafunction.
Each erase option is discussed in more detail in the following sections.
Full Erase (Device Slave Address Triggered)
The full erase option uses the A2, A1, A0 bits of the slave address to distinguish
between an erase or read/write operation. This slave operation decoding occurs when
the master transfers the slave address to the slave after generating the start condition.
If the A2, A1, and A0 slave address bits transmitted to the UFM slave equals 111 and
the four remaining MSBs match the rest of the slave addresses, then the Full Erase
operation is selected. If the A6, A5, A4, A3 A2, A1, and A0 slave address bits transmitted
to the UFM match its unique slave address setting, the read/write operation is
selected and functions as expected. As a result, this erase option utilizes two slave
addresses on the bus reserving A6, A5, A4, A3, 1, 1, 1 as the erase trigger. Both sectors
of the UFM block will be erased when the Full Erase operation is executed. This
operation requires acknowledge polling. The internal UFM erase function only begins
after the master generates a stop condition. Figure 7–13 shows the full erase sequence
triggered by using the slave address.
If the memory is write-protected (WP = 1), the slave does not acknowledge the erase
trigger slave address (A6, A5, A4, A3, 1, 1, 1) sent by the master. The master should
then send a stop condition to terminate the transfer. The full erase operation will not
be executed.
Figure 7–13. Full Erase Sequence Triggered Using the Slave Address
Slave Address
S
A
P
R/W
A A A A 111
6
5 4 3
'0' (write)
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 ]
