DSP16411 Datasheet, PDF (173/316 Pages) Agere Systems – DSP16411 Digital Signal Processor

Data Sheet
May 2003
DSP16411 Digital Signal Processor
4 Hardware Architecture (continued)
4.16 Serial Interface Unit (SIU) (continued)
4.16.12 Channel Mode—32 Channels or Less in
Two Subframes or Less (continued)
If using channel mode, the user performs the following
steps in software:
1. Configure the number of channels in the frame
structure (1 to 128) by programming the IFLIM[6:0]
field (SCON1[6:0]—see Table 104 on page 186) with
the frame size for input and the OFLIM[6:0] field
(SCON2[6:0]—see Table 105 on page 187) with the
frame size for output.
2. Configure the channel size (4 bits, 8 bits, 12 bits, or
16 bits) by writing the ISIZE[1:0] and OSIZE[1:0]
fields (SCON0[4:3] and SCON0[12:11]—see
Table 103 on page 185). Select LSB-first or MSB-
first by programming the IMSB and OMSB fields
(SCON0[2] and SCON0[10]). Configure the data
format by programming the IFORMAT[1:0] and
OFORMAT[1:0] fields (SCON0[1:0] and
SCON0[9:8]).
3. Disable frame mode by clearing the IFRAME field
(SCON1[7]—see Table 104 on page 186) and the
OFRAME field (SCON2[7]—see Table 105 on
page 187).
4. Select the number of subframes (one or two) to be
enabled. If two subframes are enabled, one must be
even and one must be odd. See step 5.
5. Select the active subframe(s) and channels within
each subframe. Tables 95 to 99 further detail the bit
fields described below:
— To activate an even input subframe, set the
ISFIDV_E field (SCON3[2]—see Table 106 on
page 188). Also program the ISFID_E[1:0] field
(SCON3[1:0]) with the address of the active even
subframe (active subframe number is
2 × ISFID_E). Within the active subframe, up to
16 logical channels can be individually enabled
via the ISFVEC_E[15:0] field (SCON4—see
Table 107 on page 189). For each enabled chan-
nel, assign one of two DMAU SWT channels by
setting or clearing the corresponding bit in ICIX0
(Table 122 on page 199).
— To activate an odd input subframe, set the
ISFIDV_O field (SCON3[5]—see Table 106 on
page 188). Also program the ISFID_O[1:0] field
(SCON3[4:3]) with the address of the active odd
subframe (active subframe number is
(2 × ISFID_O) + 1). Within the active subframe,
up to 16 logical channels can be individually
enabled via the ISFVEC_O[15:0] field
(SCON5—see Table 108 on page 189). For each
enabled channel, assign one of two DMAU SWT
channels by setting or clearing the corresponding
bit in ICIX1 (Table 122 on page 199).
— To activate an even output subframe, set the
OSFIDV_E field (SCON3[10]). Also program the
OSFID_E[1:0] field (SCON3[9:8]) with the
address of the active even subframe (active sub-
frame number is 2 × OSFID_E). Within the
active subframe, up to 16 logical channels can be
individually enabled via the OSFVEC_E[15:0]
field (SCON6—see Table 109 on page 190). Any
enabled channel can be individually masked via
the OSFMSK_E[15:0] field (SCON8—see
Table 111 on page 190). Masking an output
channel retains the data structure (the DMAU
counters are updated) but does not drive data
onto SOD for that channel period. For each
enabled channel, assign one of two DMAU SWT
channels by setting or clearing the corresponding
bit in OCIX0 (Table 121 on page 198).
— To activate an odd output subframe, set the
OSFIDV_O field (SCON3[13]). Also program the
OSFID_O[1:0] field (SCON3[12:11]) with the
address of the active odd subframe (active sub-
frame number is (2 × OSFID_O) + 1). Within the
active subframe, up to 16 logical channels can be
individually enabled via the OSFVEC_O[15:0]
field (SCON7—see Table 110 on page 190). Any
enabled channel can be individually masked via
the OSFMSK_O[15:0] field (SCON9—see
Table 112 on page 190). Masking an output
channel retains the data structure (the DMAU
counters are updated) but does not drive data
onto SOD for that channel period. For each
enabled channel, assign one of two DMAU SWT
channels by setting or clearing the corresponding
bit in OCIX1 (Table 121 on page 198).
6. Select passive vs. active bit clocks and frame syncs
(see Table 4.16.5 on page 161 for details).
7. Program the IINTSEL[1:0] field (SCON10[12:11])
OINTSEL[1:0] field (SCON10[14:13]) as required by
the application.
8. Begin processing the active channels by clearing the
IRESET field (SCON1[10]—see Table 104 on
page 186) and the ORESET field (SCON2[10]—see
Table 105 on page 187). Further user software
intervention for SIU configuration is only required to
redefine the subframe enable, the subframe ID, or
the active channels within a subframe and their
associated channel index values.
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