RM0082
LS_Synchronous serial peripheral (SSP)
Doc ID 018672 Rev 1
271/844
13.3 Signal
interfaces
The SSP directly interfaces with the signals summarized in
13.4
Main functions description
13.4.1 APB
slave
interface
The AMBA APB interface generates read and write decodes for accesses to status and
control registers, and transmit and receive FIFO memories.
The AMBA APB is a local secondary bus that provides a low-power extension to the higher
bandwidth AMBA advanced high-performance bus (AHB) within the AMBA system
Table 209.
SSP signal interface
Group
Signal name
Direction
Size (bit) Description
Global
CLK
Input
1
Main SSP clock input.
nRST
Input
1
SSP reset signal.
Interrupts
TXINTR
Output
1
Transmit FIFO service request interrupt.
RXINTR
Output
1
Receive FIFO service request interrupt.
RORINTR
Output
1
Receive overrun interrupt.
RTINTR
Output
1
Receive timeout interrupt.
INTR
Output
1
SSP interrupt. This interrupt is an OR of the
four individual interrupts TXINTR, RXINTR,
RORINTR and RTINTR.
DMA
Interface
TXDMASREQ
Output
1
Transmit DMA single request.
TXDMABREQ
Output
1
Transmit DMA burst request.
RXDMASREQ Output
1
Receive DMA single request.
RXDMABREQ Output
1
Receive DMA burst request.
TXDMACLR
Input
1
DMA request clear. Asserted by DMA
controller to clear the transmit request
signal.
RXDMACLR
Input
1
DMA request clear. Asserted by DMA
controller to clear the receive request signal.
PAD control
FSSOUT
Output
SSP frame or slave select (master mode).
CLKOUT
Output
SSP clock output (Master mode).
TXD
Output
Transmit data output.
OE
Output
Output enable signal.
FSSIN
Input
SSP frame input (slave mode).
CLKIN
Input
SSP clock input (slave mode).
RXD
Input
Receive data input.
APB Slave
-
Input/Output -
See AMBA Specification.