Datasheet

90E36A POLY-PHASE HIGH-PERFORMANCE WIDE-SPAN ENERGY METERING IC
SPI / DMA Interface 27 April 2, 2013
4 SPI / DMA INTERFACE
4.1 INTERFACE DESCRIPTION
The interface can work in two modes: Slave (SPI) mode and Master
mode, which is also named DMA (Direct Memory Access) mode. The
interface mode is determined by the DMA_CTRL pin as below:
Five pins are associated with the interface as below:
• SDI – Data pin, bi-directional.
• SDO – Data pin, bi-directional.
• SCLK – Bi-directional pin. It is a clock output pin in master mode
and clock input pin in slave mode.
• CS – Bi-directional chip select pin . It is an output pin in master
mode and input pin in slave mode.
• DMA_CTRL – Uni-directional input pin. The external device pull
this pin high to control the interface work in master mode for data
dumping in DMA mode.
Figure-12 Slave Mode
Figure-13 Master Mode (PIN_DIR_SEL=0)
Mode DMA_CTRL Description
Slave (SPI) Mode 0
The interface works as normal four-
wire SPI interface.
Master (DMA) Mode 1
The interface operates as a master
and dumps data to the other
devices.
SPI Interface logic
(As slave)
MISO
MOSI
SCK
CS
Host controller in
master mode
SCK
GPIO1
MOSI
MISO
SCLK
CS
GPIO2
DMA_CTRL
DMA_CTRL=0
SDI
SDO
SPI Interface logic
(As master)
MOSI
MISO
SCK
CS
DSP slave mode
SCK
SPISS
MOSI
MISO
SDI
SDO
SCLK
CS
DMA_CTRL=1
DMA_CTRL GPIO