Chapter 7: User Flash Memory in MAX V Devices
7–9
UFM Operating Modes
Read/Stream Read
The three control signals, PROGRAM, ERASE, and BUSYare not required during a read or
stream read operation. To perform a read operation, the address register must be
loaded with the reference address where the data is or is going to be located in the
UFM. The address register can be stopped from incrementing or shifting addresses
from ARDinby stopping the ARCLKclock pulse. DRSHFTmust be asserted low at the next
rising edge of DRCLKto load the data from the UFM to the data register. To shift the bits
from the register, 16 clock pulses must be provided to read 16-bit wide data. You can
use DRCLKto control the read time or disable the data register by discontinuing the
DRCLKclock pulse. Figure 7–5 shows the UFM control waveforms during read mode.
The UFM block can also perform a stream read operation, using the address
increment feature to read continuously from the UFM. Stream read mode is started by
loading the base address into the address register. DRSHFTmust then be asserted low at
the first rising edge of DRCLKto load data into the data register from the address
pointed to by the address register. DRSHFTwill then assert high to shift out the 16-bit
wide data with the MSB out first. Figure 7–6 shows the UFM control waveforms
during stream read mode.
Figure 7–5. UFM Read Waveforms
ARSHFT
ARCLK
ARDin
tAH
9 Address Bits
tACLK
tASU
tADH
tADS
DRSHFT
DRCLK
DRDin
16 Data Bits
tDSH
tDCLK
tDSS
tDCO
DRDout
OSC_ENA
PROGRAM
ERASE
BUSY
Figure 7–6. UFM Stream Read Waveforms
Increment
Address
Increment
Address
ARSHFT
ARCLK
ARDin
9 Address Bits
16 Data Bits
DRSHFT
DRCLK
DRDin
DRDout
OSC_ENA
PROGRAM
ERASE
BUSY
January 2011 Altera Corporation
MAX V Device Handbook
ALTERA [ ALTERA CORPORATION ]
