HD64F38602R Datasheet, PDF (335/552 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer

Section 15 Synchronous Serial Communication Unit (SSU)
15.4.6 Operation in Four-Line Bus Communication Mode
Four-line bus communication mode is a mode which communicates with the four-line bus; a clock
line, a data input line, a data output line, and a chip select line. This mode includes bidirectional
mode in which the data input line and the data output line function as a single pin. The data input
line and the data output line are changed according to the settings of the MSS and BIDE bits in
SSCRH. For details, refer to section 15.4.3, Relationship between Data Input/Output and Shift
Register. In this mode, relationship between clock polarity and phase, and data can be set by the
CPOS and CPHS bits in SSMR. For details, refer to section 15.4.2, Relationship between Clock
Polarity and Phase, and Data.
When the SSU is set as a master device, the chip select line controls output. When the SSU is set
as a slave device, the chip select line controls input. When the SSU is set as a master device, the
chip select line controls output of the SCS pin or controls output of a general port by setting the
CSS1 bit in SSCRH to 1. When the SSU is set as a slave device, the chip select line sets the SCS
pin as an input pin by setting the CSS1 and CSS0 bits in SSCRH to 01.
In four-line bus communication mode, the MLS bit in SSMR is set to 1 and transfer is performed
in MSB-first order.
Rev. 3.00 May 15, 2007 Page 303 of 518
REJ09B0152-0300