CY8C28xxx PSoC Programmable System-on-Chip TRM, Document No. 001-52594 Rev. *G
371
Digital Blocks
17.3.7
SPIM Timing
Enable/Disable Operation.
As soon as the block is config-
ured for SPIM, the primary output is the MSb or LSb of the
Shift register, depending on the LSb First configuration in bit
7 of the Control register. The auxiliary output is '1' or '0'
depending on the idle clock state of the SPI mode. This is
the idle state.
When the SPIM is enabled, the internal reset is released on
the divide-by-2 flip-flop and on the next positive edge of the
selected input clock. This 1-bit divider transitions to a '1' and
remains free-running thereafter.
When the block is disabled, the SCLK and MOSI outputs
revert to their idle state. All internal state is reset (including
CR0 status) to its configuration-specific reset state, except
for DR0, DR1, and DR2 which are unaffected.
Normal Operation.
Typical timing for a SPIM transfer is
. The user initially
writes a byte to transmit when TX Reg Empty status is true.
If no transmission is currently in progress, the data is loaded
into the shifter and the transmission is initiated. The TX Reg
Empty status is asserted again and the user is allowed to
write the next byte to be transmitted to the TX Buffer regis-
ter. After the last bit is output, if TX Buffer data is available
with one-half clock setup time to the next clock, a new byte
transmission will be initiated. A SPIM block receives a byte
at the same time that it sends one. The SPI Complete or RX
Reg Full can be used to determine when the input byte has
been received.
Figure 17-25. Typical SPIM Timing in Mode 0 and 1
INTERNAL CLOCK
TX REG EMPTY
D7
MOSI
D6
D5
D2
D1
D0
D7
User writes first
byte to the TX
Buffer register.
Shifter is loaded
with first byte.
User writes next
byte to the TX
Buffer register.
SCLK (MODE 0)
Shifter is loaded
with next byte.
Last bit of received
data is valid on this
edge and is latched
into RX Buffer.
CLK INPUT
Free running,
internal bit rate
clock is CLK input
divided by two.
Setup time
for TX
Buffer write.
SCLK (MODE 1)
RX REG FULL
First input bit
is latched.
First shift
Содержание CY8C28 series
Страница 65: ...64 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G RAM Paging ...
Страница 85: ...84 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G Internal Main Oscillator IMO ...
Страница 93: ...92 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G External Crystal Oscillator ECO ...
Страница 97: ...96 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G Phase Locked Loop PLL ...
Страница 125: ...124 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G ...
Страница 311: ...310 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G IDAC_CR0 1 FDh ...
Страница 317: ...316 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G ...
Страница 393: ...392 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G ...
Страница 425: ...424 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G Analog Reference ...
Страница 461: ...460 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G Two Column Limited Analog System ...
Страница 477: ...476 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G Digital Clocks ...
Страница 483: ...482 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G Multiply Accumulate MAC ...
Страница 513: ...512 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G Internal Voltage Reference ...
Страница 523: ...522 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G Switch Mode Pump SMP ...
Страница 533: ...532 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G I O Analog Multiplexer ...
Страница 537: ...536 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G Real Time Clock RTC ...
Страница 561: ...560 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G ...