Numonyx™ Wireless Flash Memory (W18)
If RCR[3]=1 (no-wrap mode) and RCR[2:0] = 1h (4-word burst length), then possible
linear burst sequences are 0-1-2-3, 1-2-3-4, 2-3-4-5, and 3-4-5-6. RCR[3]=1 not only
enables limited non-aligned sequential bursts, but also reduces power by minimizing
the number of internal read operations.
Setting RCR[2:0] bits for continuous linear burst mode (7h) also achieves the above 4-
word burst sequences. However, significantly more power may be consumed. The 1-2-
3-4 sequence, for example, consumes power during the initial access, again during the
internal pipeline lookup as the processor reads word 2, and possibly again, depending
on system timing, near the end of the sequence as the device pipelines the next 4-word
sequence. RCR[3]=1 while in 4-word burst mode (no-wrap mode) reduces this excess
power consumption.
14.10
Burst Length (RCR[2:0])
The Burst Length bit (BL[2:0]) selects the number of words the device outputs in
synchronous read access of the flash memory array. The burst lengths are 4-word, 8-
word, 16-word, and continuous word.
Continuous-burst accesses are linear only, and do not wrap within any word length
boundaries (see Table 35, “Sequence and Burst Length” on page 84). When a burst
cycle begins, the device outputs synchronous burst data until it reaches the end of the
“burstable” address space.
November 2007
Order Number: 290701-18
Datasheet
85
NUMONYX [ NUMONYX B.V ]
