MC68HC705CT4 Datasheet, PDF (73/152 Pages) Freescale Semiconductor, Inc – General Release Specification

Freescale Semiconductor, Inc.
Synchronous Serial Interface (SSI)
SSI Registers
being enabled. Always disable the SSI first, by clearing the SE bit, before
altering these control bits within the SSI control register (SCR).
Address: $001E
Bit 7
6
5
4
3
2
1
Bit 0
Read:
SIE
Write:
SE
LSBF MSTR CPOL T/R
SR1
SR0
Reset: 0
0
0
0
1
0
0
0
Figure 9-3. SSI Control Register (SCR)
SIE — SSI Interrupt Enable
This bit determines whether an interrupt request should be generated
when a transfer is complete.
When set, an interrupt request is made if the CPU is in the run or wait
mode of operation and status flag bit SF is set.
When cleared, no interrupt requests are made by the SSI.
SE — SSI Enable
When set, this bit enables the SSI, makes PD5 the SCK pin, and
makes PD4 the SDIO pin.
When SE is cleared, any transmission in progress is aborted, the bit
counter is reset, and pins SCK and SDIO revert to being PD5 and
PD4.
LSBF — Least Significant Bit (LSB)First
When set, data is sent and received in a least significant bit (LSB) first
format.
When cleared, data is sent and received in a most significant bit
(MSB) first format.
MSTR — Master Mode
When set, this bit configures the SSI to the master mode. This means
that the transmission is initiated by a write to the data register and the
SCK pin becomes an output providing a synchronous data clock at a
rate determined by the SR bits.
MC68HC705CT4 — Rev. 2.0
MOTOROLA
General Release Specification
Synchronous Serial Interface (SSI)
73
For More Information On This Product,
Go to: www.freescale.com