SSI Data and Control Pins
MOTOROLA
Synchronous Serial Interface (SSI)
30-35
30.4 SSI Data and Control Pins
The SSI has six I/O pins. These pins are shared with either Port B or Port C pins, depending on the
configuration of the ports. See Section 30.2.3, “Pin Configuration for SSI,” for more information. Each pin
is described in detail in the sections following Table 30-22.
30.4.1 SSI_TXDAT, Serial Transmit Data
The SSI_TXDAT pin transmits data from the TXSR. While data is being transmitted, the SSI_TXDAT pin
is an output pin. This pin is disabled between data word transmissions and on the trailing edge of the bit
clock after the last bit of a word is transmitted. This pin has an internal pull-up controlled by the GPIO’s
PUEN bit. For more information, refer to the Chapter 32, “GPIO Module and I/O Multiplexer (IOMUX).”
30.4.2 SSI_RXDAT, Serial Receive Data
The SSI_RXDAT pin brings serial data into the SSI Receive Shift Register (RXSR).
30.4.3 SSI_TXCLK, Serial Transmit Clock
The SSI_TXCLK pin can be used as either an input or an output. This clock signal is used by the
transmitter and can be either continuous or gated. During gated clock mode, data on the SSI_TXCLK pin is
valid only during the transmission of data. If the pull-up is disabled for this pin in the GPIO Module’s
Pull-Up Enable Register, then the clock pin is tri-stated when data is not transmitting. In synchronous
mode, this pin is used by both the transmit and receive sections. When using gated clock mode, an external
resistor is connected to this pin to prevent the signal from floating when not being driven.
30.4.4 SSI_RXCLK, Serial Receive Clock
The SSI_RXCLK pin can be used as either an input or an output. This clock signal is used by the receiver
and is always continuous. During gated clock mode, the SSI_TXCLK pin is used instead for clocking in
data. In I
2
S master mode, this pin is used as an output pin for the oversampling clock, SYS_CLK
(PerCLK3).
Table 30-22. SSI Pin Description
Pin Description
Pin Name
Port C
Multiplexed Pin
Port B
Multiplexed Pin
Serial Transmit Data
SSI_TXDAT
PTC [6]
PTB [17]
Serial Receive Data
SSI_RXDAT
PTC [5]
PTB [16]
Serial Transmit Clock
SSI_TXCLK
PTC [8]
PTB [19]
Serial Receive Clock
SSI_RXCLK
PTC [4]
PTB [15]
Serial Transmit Frame Sync
SSI_TXFS
PTC [7]
PTB [18]
Serial Receive Frame Sync
SSI_RXFS
PTC [3]
PTB [14]
Summary of Contents for DragonBall MC9328MX1
Page 68: ...1 12 MC9328MX1 Reference Manual MOTOROLA Introduction ...
Page 86: ...2 18 MC9328MX1 Reference Manual MOTOROLA Signal Descriptions and Pin Assignments ...
Page 116: ...3 30 MC9328MX1 Reference Manual MOTOROLA Memory Map ...
Page 126: ...4 10 MC9328MX1 Reference Manual MOTOROLA ARM920T Processor ...
Page 160: ...8 8 MC9328MX1 Reference Manual MOTOROLA System Control ...
Page 272: ...13 32 MC9328MX1 Reference Manual MOTOROLA DMA Controller ...
Page 281: ...Programming Model MOTOROLA Watchdog Timer Module 14 9 ...
Page 282: ...14 10 MC9328MX1 Reference Manual MOTOROLA Watchdog Timer Module ...
Page 300: ...15 18 MC9328MX1 Reference Manual MOTOROLA Analog Signal Processor ASP ...
Page 438: ...18 16 MC9328MX1 Reference Manual MOTOROLA Serial Peripheral Interface Modules SPI 1 and SPI 2 ...
Page 478: ...19 40 MC9328MX1 Reference Manual MOTOROLA LCD Controller ...
Page 574: ...21 32 MC9328MX1 Reference Manual MOTOROLA Memory Stick Host Controller MSHC Module ...
Page 598: ...23 16 MC9328MX1 Reference Manual MOTOROLA Real Time Clock RTC ...
Page 670: ...24 72 MC9328MX1 Reference Manual MOTOROLA SDRAM Memory Controller ...
Page 726: ...25 56 MC9328MX1 Reference Manual MOTOROLA SmartCard Interface Module SIM ...
Page 736: ...26 10 MC9328MX1 Reference Manual MOTOROLA General Purpose Timers ...
Page 854: ...29 18 MC9328MX1 Reference Manual MOTOROLA I2C Module ...
Page 900: ...30 46 MC9328MX1 Reference Manual MOTOROLA Synchronous Serial Interface SSI ...
Page 942: ...32 26 MC9328MX1 Reference Manual MOTOROLA GPIO Module and I O Multiplexer IOMUX ...