Information

Address
Address Data
TSIZ
AA=1
AA=0
AA=1
AA=0
FB_CLK
FB_A[Y]
FB_D[X]
FB_RW
FB_TS
FB_ALE
FB_CSn
FB_OEn
FB_BE/BWEn
FB_TA
FB_TSIZ[1:0]
Figure 29-43. Write Cycle with Two-Clock Address Setup and Two-Clock Hold (One Wait
State)
29.4.12 Burst cycles
The chip can be programmed to initiate burst cycles if its transfer size exceeds the port
size of the selected destination. The initiation of a burst cycle is encoded on the transfer
size pins (FB_TSIZ[1:0]). For burst transfers to smaller port sizes, FB_TSIZ[1:0]
indicates the size of the entire transfer. For example, with bursting enabled, a 16-bit
transfer to an 8-bit port takes two beats (two byte-sized transfers), for which
FB_TSIZ[1:0] equals 10b throughout. A 32-bit transfer to an 8-bit port takes four beats
(four byte-sized transfers), for which FB_TSIZ[1:0] equals 00b throughout.
29.4.12.1 Enabling and inhibiting burst
The CSCRn registers enable bursting for reads, writes, or both.
Memory spaces can be declared burst-inhibited for reads and writes by writing 0b to the
appropriate CSCRn[BSTR] and CSCRn[BSTW] fields.
Functional description
K20 Sub-Family Reference Manual, Rev. 1.1, Dec 2012
678
Preliminary
Freescale Semiconductor, Inc.
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