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TMS320VC5509A_14 Datasheet, PDF (120/145 Pages) Texas Instruments – Fixed-Point Digital Signal Processor | |||
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Electrical Specifications
Table 5â31. McBSP as SPI Master or Slave Timing Requirements (CLKSTP = 10b, CLKXP = 1)â â¡
CVDD = 1.2 V
CVDD = 1.35 V
CVDD = 1.6 V
NO.
MASTER
SLAVE
MASTER
SLAVE
UNIT
MIN MAX
MIN MAX MIN MAX
MIN MAX
MC33
tsu(DRV-CKXH)
Setup time, DR valid before CLKX
high
15
3 â 6P
10
3 â 6P
ns
MC34
th(CKXH-DRV)
Hold time, DR valid after CLKX
high
0
3 + 6P
0
3 + 6P
ns
MC36
tsu(FXL-CKXL)
Setup time, FSX low before CLKX
low
5
5
ns
MC26 tc(CKX)
Cycle time, CLKX
2P
16P
2P
16P
ns
â For all SPI slave modes, CLKG is programmed as 1/2 of the CPU clock by setting CLKSM = CLKGDV = 1.
â¡ P = 1/CPU clock frequency. For example, when running parts at 200 MHz, use P = 5 ns. In addition to CPU frequency, the maximum operating
frequency of the serial port also depends on meeting the rest of the switching characteristics and timing requirements parameters specified.
Table 5â32. McBSP as SPI Master or Slave Switching Characteristics (CLKSTP = 10b, CLKXP = 1)â â¡
NO.
PARAMETER
CVDD = 1.2 V
CVDD = 1.35 V
MASTER§
SLAVE
CVDD = 1.6 V
MASTER§
SLAVE
UNIT
MIN MAX
MIN MAX
MIN MAX
MIN MAX
MC37 td(CKXH-FXL)
Delay time, CLKX high
to FSX low¶
Tâ5
T+5
Tâ4 T+4
ns
MC38 td(FXL-CKXL)
Delay time, FSX low to
CLKX low#
Dâ5
D+5
Dâ4 D+4
ns
MC35 td(CKXL-DXV)
Delay time, CLKX low to
DX valid
â4
6 3P + 3 5P + 15
â3
3 3P + 3 5P + 8 ns
MC39
tdis(CKXH-DXHZ)
Disable time, DX high-
impedance following
last data bit from CLKX
high
Dâ4
D+4
Dâ3 D+1
ns
MC31
tdis(FXH-DXHZ)
Disable time, DX high-
impedance following
last data bit from FSX
high
3P + 4 3P +19
3P + 3 3P +11 ns
MC32 td(FXL-DXV)
Delay time, FSX low to
DX valid
3P + 4 3P + 18
3P + 4 3P + 10 ns
â For all SPI slave modes, CLKG is programmed as 1/2 of the CPU clock by setting CLKSM = CLKGDV = 1.
â¡ P = 1/CPU clock frequency. For example, when running parts at 200 MHz, use P = 5 ns. In addition to CPU frequency, the maximum operating
frequency of the serial port also depends on meeting the rest of the switching characteristics and timing requirements parameters specified.
§ T = CLKX period = (1 + CLKGDV) * P
C = CLKX low pulse width = T/2 when CLKGDV is odd or zero and = (CLKGDV/2) * P when CLKGDV is even
D = CLKX high pulse width = T/2 when CLKGDV is odd or zero and = (CLKGDV/2 + 1) * P when CLKGDV is even
¶ FSRP = FSXP = 1. As a SPI master, FSX is inverted to provide active-low slave-enable output. As a slave, the active-low signal input on FSX
and FSR is inverted before being used internally.
CLKXM = FSXM = 1, CLKRM = FSRM = 0 for master McBSP
CLKXM = CLKRM = FSXM = FSRM = 0 for slave McBSP
# FSX should be low before the rising edge of clock to enable slave devices and then begin a SPI transfer at the rising edge of the master clock
(CLKX).
120 SPRS205K
November 2002 â Revised January 2008
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