TMSC6701 Datasheet, PDF (49/64 Pages) Texas Instruments – FLOATING POINT DIGITAL SIGNAL PROCESSOR

TMS320C6701
FLOATINGĆPOINT DIGITAL SIGNAL PROCESSOR
SPRS067E – MAY 1998 – REVISED MAY 2000
MULTICHANNEL BUFFERED SERIAL PORT TIMING
timing requirements for McBSP^†‡ (see Figure 31)
’C6701-120
’C6701-150
NO.
’C6701-167 ^UNIT
2 tc(CKRX)
3 tw(CKRX)
Cycle time, CLKR/X
Pulse duration, CLKR/X high or CLKR/X low
5 tsu(FRH-CKRL) Setup time, external FSR high before CLKR low
CLKR/X ext
CLKR/X ext
CLKR int
CLKR ext
MIN MAX
2P§
ns
P – 1¶
ns
13
ns
4
6 th(CKRL-FRH) Hold time, external FSR high after CLKR low
CLKR int
7
ns
CLKR ext
4
7 tsu(DRV-CKRL) Setup time, DR valid before CLKR low
CLKR int
10
ns
CLKR ext
1
8 th(CKRL-DRV) Hold time, DR valid after CLKR low
CLKR int
4
ns
CLKR ext
4
10 tsu(FXH-CKXL) Setup time, external FSX high before CLKX low
CLKX int
13
ns
CLKX ext
4
11 th(CKXL-FXH)
Hold time, external FSX high after CLKX low
CLKX int
7
ns
CLKX ext
3
† _{P = 1/CPU clock frequency in ns. For example, when running parts at 167 MHz, use P = 6 ns.}
‡ _{CLKRP = CLKXP = FSRP = FSXP = 0. If polarity of any of the signals is inverted, then the timing references of that signal are also inverted.}
§ _{The maximum McBSP bit rate is 50 MHz; therefore, the minimum CLKR/X clock cycle is either twice the CPU cycle time (2P), or 20 ns (50 MHz),}
whichever value is larger. For example, when running parts at 167 MHz (P = 6 ns), use 20 ns as the minimum CLKR/X clock cycle (by setting
the appropriate CLKGDV ratio or external clock source). When running parts at 80 MHz (P = 12.5 ns), use 2P = 25 ns (40 MHz) as the minimum
CLKR/X clock cycle. The maximum McBSP bit rate applies when the serial port is a master of clock and frame syncs and the other device the
McBSP communicates to is a slave.
¶ _{The minimum CLKR/X pulse duration is either (P–1) or 9 ns, whichever is larger. For example, when running parts at 167 MHz (P = 6 ns), use}
9 ns as the minimum CLKR/X pulse duration. When running parts at 80 MHz (P = 12.5 ns), use (P–1) = 11.5 ns as the minimum CLKR/X pulse
duration.
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