mc68hc908as60 Freescale Semiconductor, Inc, mc68hc908as60 Datasheet - Page 288

• Manufacturer Part Number: mc68hc908as60
• Description: Mc68hc908as60 Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Serial Peripheral Interface (SPI)
18.14.3 SPI Data Register
Technical Data
SPR1 and SPR0 — SPI Baud Rate Select Bits
Use this formula to calculate the SPI baud rate:
where:
The SPI data register is the read/write buffer for the receive data register
and the transmit data register. Writing to the SPI data register writes data
into the transmit data register. Reading the SPI data register reads data
from the receive data register. The transmit data and receive data
registers are separate buffers that can contain different values. See
Figure
If the MODFEN bit is low, the level of the SS pin does not affect the
operation of an enabled SPI configured as a master. For an enabled
SPI configured as a slave, having MODFEN low only prevents the
MODF flag from being set. It does not affect any other part of SPI
operation. (See
In master mode, these read/write bits select one of four baud rates as
shown in
Reset clears SPR1 and SPR0.
CGMOUT = base clock output of the clock generator module (CGM);
see
BD = baud rate divisor
Freescale Semiconductor, Inc.
For More Information On This Product,
Section 10. Clock Generator Module (CGM)
18-2.
Baud rate
Serial Peripheral Interface (SPI)
Table
Go to: www.freescale.com
Table 18-5. SPI Master Baud Rate Selection
SPR1:SPR0
18-5. SPR1 and SPR0 have no effect in slave mode.
18.7.2 Mode Fault
00
01
10
11
=
CGMOUT
------------------------- -
2 BD
Baud Rate Divisor (BD)
Error.)
128
32
MC68HC908AS60 — Rev. 1.0
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