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TMS320VC5509A_14 Datasheet, PDF (120/145 Pages) Texas Instruments – Fixed-Point Digital Signal Processor
Electrical Specifications
Table 5−31. McBSP as SPI Master or Slave Timing Requirements (CLKSTP = 10b, CLKXP = 1)†‡
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 − 6P
10
3 − 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
† For all SPI slave modes, CLKG is programmed as 1/2 of the CPU clock by setting CLKSM = CLKGDV = 1.
‡ 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 5−32. McBSP as SPI Master or Slave Switching Characteristics (CLKSTP = 10b, CLKXP = 1)†‡
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¶
T−5
T+5
T−4 T+4
ns
MC38 td(FXL-CKXL)
Delay time, FSX low to
CLKX low#
D−5
D+5
D−4 D+4
ns
MC35 td(CKXL-DXV)
Delay time, CLKX low to
DX valid
−4
6 3P + 3 5P + 15
−3
3 3P + 3 5P + 8 ns
MC39
tdis(CKXH-DXHZ)
Disable time, DX high-
impedance following
last data bit from CLKX
high
D−4
D+4
D−3 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
† For all SPI slave modes, CLKG is programmed as 1/2 of the CPU clock by setting CLKSM = CLKGDV = 1.
‡ 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 − Revised January 2008