SMC Networks AHB SRAM/NOR, PL241 manual 11 lists the register bit assignments, Bits, Name, Function

Models: AHB SRAM/NOR PL241

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Table 3-11lists the register bit assignments.

Programmer’s Model

Table 3-11lists the register bit assignments.

 

 

 

Table 3-11 smc_opmode Register bit assignments

 

 

 

Bits

Name

Function

 

 

 

[31:24]

address_match

Returns the value of this tie-off. This is the comparison value for address bits [31:24] to

 

 

determine the chip that is selected.

 

 

 

[23:16]

address_mask

Returns the value of this tie-off. This is the mask for address bits[31:24] to determine the

 

 

chip that must be selected. A logic 1 indicates the bit is used for comparison.

 

 

 

[15:13]

burst_align

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

 

 

 

rd_sync = 0

 

 

the AHB MC always aligns write bursts to the memory burst boundary, when

 

 

 

wr_sync = 0.

 

 

 

 

 

 

 

[12]

bls

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 8-bit memories that have

 

 

no Byte Lane Strobe 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]

adv

The memory uses the address advance signal smc_adv_n_0 when set.

 

 

 

[10]

baa

The memory uses the burst advance signal smc_baa_n_0 when set.

 

 

 

[9:7]

wr_bl

Determines the memory burst length for writes:

 

 

b000

= 1 beat

 

 

b001

= 4 beats

 

 

b010

= 8 beats

 

 

b011

= 16 beats

 

 

b100

= 32 beats

 

 

b101

= continuous

b110-b111 = reserved.

ARM DDI 0389B

Copyright © 2006 ARM Limited. All rights reserved.

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Page 77
Image 77
SMC Networks AHB SRAM/NOR, PL241 manual 11 lists the register bit assignments, Bits, Name, Function