TMP92CF30
2009-06-12
92CF30-461
Differences Between the UNIT-mode and Sequential-mode transmissions
The UNIT mode for the data transmission can be selected by writing a “0” to the
SPICT<TXMOD> bit.
The transmit FIFO buffer is disabled in UNIT mode. The UNIT-mode transmission starts
when the UNIT-size data is loaded into the SPITD register where SPICT<TXE> = “1”, or
when the SPICT<TXE> is set to “1” after loading one UNIT-size data into the SPITD
register. During the data transmission, it is prohibited to change the transmission mode
from Sequential to UNIT, or vice versa.
In the UNIT-mode transmission, the TEMP interrupt is generated when the transmit
data is loaded from the transmit data register (SPITD) to the transmit shift register. Also,
the TEND interrupt is generated upon completion of the transmission of the last UNIT
data.
Important Note:
When in UNIT mode (TXMOD = “0”), the following restriction is imposed on the
system operation.
When the SPICT<TEX> bit is set to “1”, the state of any bits must not be changed
until the data transmission is completed.
Sample Program 1:
LD
(SPITDx), A
; Load the transmit data
DI
; Disable the interrupt
SET 3,
(SPICT)
; Start transmission by setting the TXE bit to “1”
Wait:
BIT 1,
(SPIST)
; Wait for the completion of the transmission
JPZ, Wait
RES 3,
(SPICT)
; Disable the transmission by clearing the TXE bit to “0”
EI
; Enable the interrupt
Sample Program 2 (Recommend):
Check the transmission end flag. (SPIST<TEND> = “1”)
LD
(SPITDx), A
; Load “A” the transmit data
DI
; Disable the interrupt
SET 3,
(SPICT)
; Start transmission be setting the TXE bit to “1”
RES 3,
(SPICT)
; Disable the transmission by clearing the TXE bit to “0”
EI
; Enable the interrupt
The Sequential mode for the data transmission can be selected by writing a “1” to the
SPICT<TXMOD> bit. The 32-byte FIFO is enabled in Sequential mode.
In this mode, the data writes to the transmit FIFO must be performed in 16-byte units.
Otherwise, the TEMP interrupt is not properly generated.
In the Sequential-mode transmission, transmit data written into the SPITD is loaded
sequentially when SPICT<TXE> = “1”. The transmission in this mode can also be started
by setting the SPICT<TXE> bit to “1” after writing the transmit data into the transmit
FIFO. The transmit data is transmitted in the same order as they were written into the
FIFO.
This mode of transmission keeps transmitting data as long as the transmit data exists.
Therefore, the Sequential-mode transmission continues as long as the transmit FIFO (32
bytes) has any valid data. During the data transmission, it is prohibited to change the
transmission mode from Sequential to UNIT, or vice versa.
Summary of Contents for TLCS-900/H1 Series
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