ADV
ANCEINFORMA
TION
Bit 0
Bit(n-1)
(n-2)
(n-3)
(n-4)
Bit 0
Bit(n-1)
(n-2)
(n-3)
(n-4)
CLKX
FSX
DX
DR
M35
M37
M40
M39
M38
M34
LSB
MSB
M41
M42
TMS320F28377S, TMS320F28376S, TMS320F28375S, TMS320F28374S
SPRS881A – AUGUST 2014 – REVISED JUNE 2015
Table 5-68. McBSP as SPI Master or Slave Timing Requirements (CLKSTP = 11b, CLKXP = 0)
MASTER
SLAVE
NO.
UNIT
MIN
MAX
MIN
MAX
M39
t
su(DRV-CKXH)
Setup time, DR valid before CLKX high
30
8P – 10
ns
M40
t
h(CKXH-DRV)
Hold time, DR valid after CLKX high
1
8P – 10
ns
M41
t
su(FXL-CKXH)
Setup time, FSX low before CLKX high
16P + 10
ns
M42
t
c(CKX)
Cycle time, CLKX
2P
(1)
16P
ns
(1)
2P = 1/CLKG
Table 5-69. McBSP as SPI Master or Slave Switching Characteristics Over Recommended Operating
Conditions (Unless Otherwise Noted) (CLKSTP = 11b, CLKXP = 0)
MASTER
SLAVE
NO.
PARAMETER
UNIT
MIN
MAX
MIN
MAX
M34
t
h(CKXL-FXL)
Hold time, FSX low after CLKX low
P
ns
M35
t
d(FXL-CKXH)
Delay time, FSX low to CLKX high
2P
(1)
ns
M37
t
dis(CKXL-DXHZ)
Disable time, DX high impedance following last data bit
P + 6
7P + 6
ns
from CLKX low
M38
t
d(FXL-DXV)
Delay time, FSX low to DX valid
6
4P + 6
ns
(1)
2P = 1/CLKG
For all SPI slave modes, CLKX must be a minimum of eight CLKG cycles. Also, CLKG should be
LSPCLK/2 by setting CLKSM = CLKGDV = 1. With a maximum LSPCLK speed of 75 MHz, CLKX
maximum frequency is LSPCLK/16; that is, 4.6875 MHz and P = 13.3 ns.
Figure 5-53. McBSP Timing as SPI Master or Slave: CLKSTP = 11b, CLKXP = 0
Copyright © 2014–2015, Texas Instruments Incorporated
Specifications
135
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