Motorola Spi Frame Format - Sharp Blue Treak LH75400 User Manual

LH75400/01/10/11 (Preliminary) User's Guide

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.
NOTES
1. Single transfer: SPH = '0', SPO = '0'.
2. Q = Undefined.
NOTE: Continuous transfer: SPH = '1', SPO = '0'.
SSPCLK
SSPFRM
MSB
SSPTX
SSPRX MSB
Figure 18-3. Motorola SPI Frame Format (Single Transfer)
SSPCLK
SSPFRM
SSPTX/
MSB
SSPRX
Figure 18-4. Motorola SPI Frame Format (Continuous Transfer)
4 to 16 BITS
4 to 16 BITS
6/17/03
Synchronous Serial Port
LSB
LSB Q
LH754xx-31
LSB
LH754xx-32
18-5