SMC Networks ARM PL241 - Manual (Page 73)

Programmer’s Model
ARM DDI 0389B Copyright © 2006 ARM Limited. All rights reserved. 3-13
Table 3-8 lists the register bit assignments.
Table 3-8 smc_set_opmode Register bit assignments
Bits Name Function
[31:16] - Reserved, undefined, write as zero.
[15:13] set_burst_align Holding register for value to be written to the specific SRAM chip opmode Register
burst_align field.
These bits determine whether memory bursts are split on memory burst boundaries:
000 = bursts can cross any address boundary
001 = burst split on memory burst boundary, that is, 32 beats for continuous
010 = burst split on 64 beat boundary
011 = burst split on 128 beat boundary
100 = burst split on 256 beat boundary
others = reserved.
Note
For asynchronous transfers:
• the AHB MC always aligns read bursts to the memory burst boundary, when
set_rd_sync = 0
• the AHB MC always aligns write bursts to the memory burst boundary, when
set_wr_sync = 0.
[12] set_bls Holding register for value to be written to the specific SRAM chip smc_opmode Register
byte lane strobe (bls) field. This bit affects the assertion of the byte-lane strobe outputs.
b0 = bls timing equals chip select timing. This is the default setting.
b1 = bls timing equals smc_we_n_0 timing. This setting is used for eight bit wide memories
that have no smc_bls_n_0[3:0] inputs. In this case the smc_bls_n_0[3:0] output of the
memory controller is connected to the smc_we_n_0 memory input.
[11] set_adv Holding register for the value to be written to the specific SRAM chip smc_opmode Register
address valid (adv) field. The memory uses the address advance signal smc_adv_n_0 when
set.
[10] set_baa Holding register for value to be written to the specific SRAM chip smc_opmode Register
Burst Address Advance (baa) field. The memory uses the smc_baa_n_0 signal when set.