ꢀ ꢁꢂ ꢃ ꢄ ꢅ ꢆꢇ ꢈ ꢉꢈ ꢀꢊ ꢀ ꢁꢂ ꢃ ꢄ ꢅ ꢆꢇ ꢈ ꢉꢋ ꢀꢊ ꢀ ꢁꢂ ꢃ ꢄꢅ ꢆꢇ ꢈꢉ ꢇꢀ
ꢌ ꢍꢎ ꢏꢐꢑꢒꢓ ꢍ ꢔꢀ ꢐꢍ ꢕꢍ ꢀꢖꢗ ꢂꢍ ꢕ ꢔꢖꢗ ꢒꢘ ꢓ ꢆꢏ ꢂ ꢂꢓ ꢘ ꢂ
SPRS226H − NOVEMBER 2003 − REVISED AUGUST 2005
MULTICHANNEL BUFFERED SERIAL PORT (McBSP) TIMING
†
timing requirements for McBSP (see Figure 51)
−600
−720
−850
−1G
NO.
UNIT
MIN
4P or 6.67
MAX
द
2
3
t
t
Cycle time, CLKR/X
CLKR/X ext
CLKR/X ext
CLKR int
CLKR ext
CLKR int
CLKR ext
CLKR int
CLKR ext
CLKR int
CLKR ext
CLKX int
CLKX ext
CLKX int
CLKX ext
ns
ns
c(CKRX)
#
− 1
Pulse duration, CLKR/X high or CLKR/X low
0.5t
w(CKRX)
c(CKRX)
9
5
6
t
t
t
t
t
t
Setup time, external FSR high before CLKR low
Hold time, external FSR high after CLKR low
Setup time, DR valid before CLKR low
ns
ns
ns
ns
ns
ns
su(FRH-CKRL)
h(CKRL-FRH)
su(DRV-CKRL)
h(CKRL-DRV)
su(FXH-CKXL)
h(CKXL-FXH)
1.3
6
3
8
7
0.9
3
8
Hold time, DR valid after CLKR low
3.1
9
10
11
Setup time, external FSX high before CLKX low
Hold time, external FSX high after CLKX low
1.3
6
3
†
‡
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 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/CPU clock frequency in ns. For example, when running parts at 600 MHz, use P = 1.67 ns.
§
¶
#
Use whichever value is greater.
This parameter applies to the maximum McBSP frequency. Operate serial clocks (CLKR/X) in the reasonable range of 40/60 duty cycle.
117
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