TMS320C6211, TMS320C6211B
FIXED-POINT DIGITAL SIGNAL PROCESSORS
SPRS073K
AUGUST 1998
REVISED MARCH 2004
74
POST OFFICE BOX 1443
HOUSTON, TEXAS 77251
1443
MULTICHANNEL BUFFERED SERIAL PORT TIMING (CONTINUED)
timing requirements for McBSP as SPI master or slave: CLKSTP = 10b, CLKXP = 1
(see Figure 41)
NO.
150
167
UNIT
MASTER
MIN
26
4
SLAVE
MIN
2
6P
6 + 12P
MAX
MAX
4
5
t
su(DRV-CKXH)
t
h(CKXH-DRV)
Setup time, DR valid before CLKX high
Hold time, DR valid after CLKX high
ns
ns
P = 1/CPU clock frequency in ns. For example, when running parts at 167 MHz, use P = 6 ns.
For all SPI slave modes, CLKG is programmed as 1/2 of the CPU clock by setting CLKSM = CLKGDV = 1.
switching characteristics over recommended operating conditions for McBSP as SPI master or
slave: CLKSTP = 10b, CLKXP = 1
(see Figure 41)
NO.
PARAMETER
150
167
UNIT
MASTER
§
MIN
T
9
H
9
9
SLAVE
MIN
MAX
T + 9
H + 9
MAX
1
2
3
t
h(CKXH-FXL)
t
d(FXL-CKXL)
t
d(CKXL-DXV)
Hold time, FSX low after CLKX high
Delay time, FSX low to CLKX low
#
Delay time, CLKX low to DX valid
Disable time, DX high impedance following last data bit from
CLKX high
ns
ns
ns
9
6P + 4
10P + 20
6
t
dis(CKXH-DXHZ)
H
9
H + 9
ns
7
t
dis(FXH-DXHZ)
Disable time, DX high impedance following last data bit from
FSX high
2P + 3
6P + 20
ns
8
t
d(FXL-DXV)
Delay time, FSX low to DX valid
4P + 2
8P + 20
ns
P = 1/CPU clock frequency in ns. For example, when running parts at 167 MHz, use P = 6 ns.
For all SPI slave modes, CLKG is programmed as 1/2 of the CPU clock by setting CLKSM = CLKGDV = 1.
§
S =
Sample rate generator input clock = 2P if CLKSM = 1 (P = 1/CPU clock frequency)
=
Sample rate generator input clock = P_clks if CLKSM = 0 (P_clks = CLKS period)
T =
CLKX period = (1 + CLKGDV) * S
H =
CLKX high pulse width = (CLKGDV/2 + 1) * S if CLKGDV is even
= (CLKGDV + 1)/2 * S if CLKGDV is odd or zero
L =
CLKX low pulse width
= (CLKGDV/2) * S if CLKGDV is even
= (CLKGDV + 1)/2 * S if CLKGDV is odd or zero
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).