External Memory Controller (EMC)
Symphony DSP56724/DSP56725 Multi-Core Audio Processors, Rev. 0
Freescale Semiconductor
21-13
Table 21-10. ORHx-GPCM Field Descriptions
Bits
Name
Description
23–10
—
Reserved
9–0
AM
GPCM address mask bits 23–14. Masks correspond to BR
x bits. Masking address bits
independently allows external devices of different size address ranges to be used. Address mask
bits can be set or cleared in any order in the field, allowing a resource to reside in more than one
area of the address map.
0 Corresponding address bits are masked.
1 Corresponding address bits are used in the comparison between base and transaction
addresses.
Table 21-11. Option Register Low Part - GPCM Mode(x)
ORLx
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
ORL0 X:$FF_FE02
ORL1 X:$FF_FE06
ORL2 X:$FF_FE0A
ORL3 X:$FF_FE0E
ORL4 X:$FF_FE12
ORL5 X:$FF_FE16
ORL6 X:$FF_FE1A
ORL7 X:$FF_FE1E
R
AM
XAM
BCTLD
W
R
CSNT
ACS
XACS
SCY
SETA
TRLX EHTR
EAD
W
Reset
0x00_0FF7(ORL0); 0x00_0000 (all other ORLx)
1
ORH0 has this value set during reset (GPCM is the default control machine for all banks coming out of reset). All other option
registers have all bits cleared.
Table 21-12. ORL
x
-GPCM Field Descriptions
Bits
Name
Description
23–16
—
Reserved
15
AM
GPCM address mask bit 13. Masks corresponding BR
x bits. Masking address bits independently allows
external devices of different size address ranges to be used. Address mask bits can be set or cleared in
any order in the field, allowing a resource to reside in more than one area of the address map.
0 Corresponding address bits are masked.
1 Corresponding address bits are used in the comparison between base and transaction addresses.
14–13
XAM
Extended address mask. Masks the corresponding XBA bits in the BRx register. For example, if BRx[XBA]
= 00 or 01, and ORx[XAM] = 10, then the settings permit access from both X and Y.
12
BCTLD
Buffer control disable. Disables assertion of LBCTL during access to the current memory bank.
0 LBCTL is asserted upon access to the current memory bank.
1 LBCTL is not asserted upon access to the current memory bank.