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P
TMS320DM6446
Digital Media System on-Chip
SPRS283–DECEMBER 2005
Table 5-79. Switching Characteristics Over Recommended Operating Conditions for ASP
(1)(2)
(see
Figure 5-59
)
-594
MIN
NO.
PARAMETER
UNIT
MAX
2
3
t
c(CKRX)
t
w(CKRX)
Cycle time, CLKR/X
Pulse duration, CLKR/X high or CLKR/X low
CLKR/X int
CLKR/X int
CLKR int
CLKR ext
CLKX int
CLKX ext
CLKX int
CLKX ext
CLKX int
CLKX ext
FSX int
38.5
(3)(4)
C - 1
(5)
ns
ns
C + 1
(5)
-2.1
1.7
-1.7
1.7
-3.9
2.1
3
4
3
4
4
4
4
t
d(CKRH-FRV)
Delay time, CLKR high to internal FSR valid
ns
9
t
d(CKXH-FXV)
Delay time, CLKX high to internal FSX valid
ns
Disable time, DX high impedance following last data
bit from CLKX high
12
t
dis(CKXH-DXHZ)
ns
-3.9 + D1
(6)
2.1 + D1
(6)
-2.3 + D1
(7)
4 + D2
(6)
4 + D2
(6)
4 + D2
(7)
ns
ns
13
t
d(CKXH-DXV)
Delay time, CLKX high to DX valid
Delay time, FSX high to DX valid
ONLY applies when in data
delay 0 (XDATDLY = 00b) mode
14
t
d(FXH-DXV)
ns
FSX ext
1.9 + D1
(7)
4 + D2
(7)
(1)
CLKRP = CLKXP = FSRP = FSXP = 0. If polarity of any of the signals is inverted, then the timing references of that signal are also
inverted.
Minimum delay times also represent minimum output hold times.
Minimum CLKR/X cycle times must be met, even when CLKR/X is generated by an internal clock source. Minimum CLKR/X cycle times
are based on internal logic speed; the maximum usable speed may be lower due to EDMA limitations and AC timing requirements.
P = 1/DSP CPU clock frequency in ns. For example, when running parts at 594 MHz, use P = 1.68 ns.
C = H or L
S = sample rate generator input clock = 4P if CLKSM = 1 (P = 1/CPU clock frequency)
S = sample rate generator input clock = Not Supported if CLKSM = 0 (no CLKS pin on DM6446)
H = CLKX high pulse width = (CLKGDV/2 + 1) * S if CLKGDV is even
H = (CLKGDV + 1)/2 * S if CLKGDV is odd or zero
L = CLKX low pulse width = (CLKGDV/2) * S if CLKGDV is even
L = (CLKGDV + 1)/2 * S if CLKGDV is odd or zero
CLKGDV should be set appropriately to ensure the ASP bit rate does not exceed the maximum limit (see footnote above).
Extra delay from CLKX high to DX valid
applies
only
to the first data bit of a device
, if and only if DXENA = 1 in SPCR.
if DXENA = 0, then D1 = D2 = 0
if DXENA = 1, then D1 = 4P, D2 = 8P
Extra delay from FSX high to DX valid
applies
only
to the first data bit of a device
, if and only if DXENA = 1 in SPCR.
if DXENA = 0, then D1 = D2 = 0
if DXENA = 1, then D1 = 4P, D2 = 8P
(2)
(3)
(4)
(5)
(6)
(7)
Peripheral and Electrical Specifications
191