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SMJ320VC5416HFGW10 Datasheet, PDF (81/96 Pages) Texas Instruments – Fixed-Point Digital Signal Processor | |||
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Electrical Specifications
Table 5--27. McBSP as SPI Master or Slave Timing Requirements (CLKSTP = 11b, CLKXP = 0)â
5416-100
MASTER
SLAVE
UNIT
MIN MAX
MIN MAX
tsu(BDRV-BCKXL)
th(BCKXH-BDRV)
Setup time, BDR valid before BCLKX low
Hold time, BDR valid after BCLKX high
12
2.2 -- 6P*â¡
ns
4
5 + 12P*â¡
ns
* Not production tested.
â For all SPI slave modes, CLKG is programmed as 1/2 of the CPU clock by setting CLKSM = CLKGDV = 1.
â¡ P = 1 / (2 * processor clock)
Table 5--28. McBSP as SPI Master or Slave Switching Characteristics (CLKSTP = 11b, CLKXP = 0)â
PARAMETER
5416-100
MASTER§
SLAVE
UNIT
th(BCKXL-BFXL)
td(BFXL-BCKXH)
td(BCKXL-BDXV)
tdis(BCKXL-BDXHZ)
MIN MAX
MIN
MAX
Hold time, BFSX low after BCLKX low¶
C --3* C + 4
ns
Delay time, BFSX low to BCLKX high#
T -- 4* T + 3*
ns
Delay time, BCLKX low to BDX valid
-- 4*
5 6P + 2*â¡ 10P + 17â¡ ns
Disable time, BDX high impedance following last data bit from
BCLKX low
-- 2*
4* 6P -- 4*â¡ 10P + 17*â¡ ns
td(BFXL-BDXV)
Delay time, BFSX low to BDX valid
D -- 2* D + 4* 4P + 2*â¡ 8P + 17*â¡ ns
* Not production tested.
â For all SPI slave modes, CLKG is programmed as 1/2 of the CPU clock by setting CLKSM = CLKGDV = 1.
â¡ P = 1 / (2 * processor clock)
§ T = BCLKX period = (1 + CLKGDV) * 2P
C = BCLKX low pulse width = T/2 when CLKGDV is odd or zero and = (CLKGDV/2) * 2P when CLKGDV is even
D = BCLKX high pulse width = T/2 when CLKGDV is odd or zero and = (CLKGDV/2 + 1) * 2P when CLKGDV is even
¶ FSRP = FSXP = 1. As a SPI master, BFSX is inverted to provide active-low slave-enable output. As a slave, the active-low signal input on BFSX
and BFSR is inverted before being used internally.
CLKXM = FSXM = 1, CLKRM = FSRM = 0 for master McBSP
CLKXM = CLKRM = FSXM = FSRM = 0 for slave McBSP
# BFSX 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
(BCLKX).
BCLKX
LSB
MSB
BFSX
tdis(BCKXL-BDXHZ)
BDX
Bit 0
BDR
Bit 0
th(BCKXL-BFXL)
td(BFXL-BDXV)
tsu(BDRV-BCKXL)
td(BFXL-BCKXH)
Bit(n-1)
Bit(n-1)
td(BCKXL-BDXV)
(n-2)
(n-3)
th(BCKXH-BDRV)
(n-2)
(n-3)
(n-4)
(n-4)
Figure 5--25. McBSP Timing as SPI Master or Slave: CLKSTP = 11b, CLKXP = 0
April 2003 -- Revised July 2003
SGUS035A
71
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