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LH75400/01/10/11 (Preliminary) User’s Guide
Synchronous Serial Port
6/17/03
18-5
18.3.1 Motorola SPI Frame Format
For the Motorola SPI format, the serial frame pin (SSPFRM) is active LOW. The SPO and
SPH bits in SSP Control Register 0 influence SSPCLK and SSPFRM operation in Single
and Continuous Modes.
Figure 18-3 through Figure 18-6 show the Motorola SPI frame format for single data trans-
fers, continuous data transfers, and when SPH equals 0 or 1.
Figure 18-3. Motorola SPI Frame Format (Single Transfer)
Figure 18-4. Motorola SPI Frame Format (Continuous Transfer)
SSPRX
NOTES
1. Single transfer: SPH = '0', SPO = '0'.
2. Q = Undefined.
SSPTX
SSPFRM
SSPCLK
4 to 16 BITS
MSB
MSB
LSB
Q
LSB
LH754xx-31
NOTE: Continuous transfer: SPH = '1', SPO = '0'.
SSPFRM
SSPCLK
SSPTX/
SSPRX
4 to 16 BITS
MSB
LSB
LH754xx-32