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Synchronous Serial Interface (SSI)
27-14
Freescale Semiconductor
7
MCE
Master clock enable. Allows the SSI to output the master clock at the SSI_MCLK port, if network mode and transmit
internal clock mode are set. The DIV2, PSR, and PM bits determine the relationship between the bit clock
(SSI_BCLK) and SSI_MCLK. In I
2
S master mode, this bit is used to output the oversampling clock on SSI_MCLK.
0 Master clock not output on the SSI_MCLK pin
1 Master clock output on the SSI_MCLK pin
6–5
I2S
I
2
S mode select. Selects normal, I
2
S master, or I
2
for a detailed
description of I
2
S mode.
00 Normal mode
01 I
2
S master mode
10 I
2
S slave mode
11 Normal mode
4
SYN
Synchronous mode enable. In synchronous mode, transmit and receive sections of SSI share a common clock port
(SSI_BCLK) and frame sync port (SSI_FS).
0 Reserved.
1 Synchronous mode selected.
3
NET
Network mode enable.
0 Network mode not selected
1 Network mode selected
2
RE
Receiver enable. When this bit is set, data reception starts with the arrival of the next frame sync. If data is received
when this bit is cleared, data reception continues with the end of the current frame and then stops. If this bit is set
again before the second to last bit of the last time slot in the current frame, reception continues without interruption.
0 Receiver disabled
1 Receiver enabled
1
TE
Transmitter. Enables the transfer of the contents of the SSI_TX registers to the TXSR, and also enables the internal
transmit clock. The transmit section is enabled when this bit is set and a frame boundary is detected.
When this bit is cleared, the transmitter continues to send data until the end of the current frame and then stops.
Data can be written to the SSI_TX registers with the TE bit cleared (the corresponding TDE bit is cleared). If the TE
bit is cleared and set again before the second to last bit of the last time slot in the current frame, data transmission
continues without interruption.
The normal transmit enable sequence is to:
1. Write data to the SSI_TX register(s)
2. Set the TE bit
The normal transmit disable sequence is to:
1. Wait for TDE to set
2. Clear the TE and TIE bits
In gated clock mode, clearing the TE bit results in the clock stopping after the data currently in TXSR has shifted out.
When the TE bit is set, the clock starts immediately in internal gated clock mode.
0 Transmitter disabled
1 Transmitter enabled
0
SSI_EN
SSI enable. When disabled, all SSI status bits are reset to the same state produced by the power-on reset, all control
bits are unaffected, and the contents of Tx and Rx FIFOs are cleared. When SSI is disabled, all internal clocks are
disabled (except the register access clock).
0 SSI module is disabled
1 SSI module is enabled
Table 27-7. SSI_CR Field Descriptions (continued)
Field
Description
Summary of Contents for MCF54455
Page 33: ...xxviii Freescale Semiconductor ...
Page 67: ...Freescale Semiconductor 1 ...
Page 125: ...Freescale Semiconductor 1 ...
Page 145: ...Enhanced Multiply Accumulate Unit EMAC 5 21 Freescale Semiconductor ...
Page 173: ...Cache 6 28 Freescale Semiconductor ...
Page 179: ...Static RAM SRAM 7 6 Freescale Semiconductor ...
Page 207: ...Power Management 9 16 Freescale Semiconductor ...
Page 323: ...Reset Controller Module 13 8 Freescale Semiconductor ...
Page 389: ...Pin Multiplexing and Control 16 44 Freescale Semiconductor ...
Page 575: ...PCI Bus Controller 22 58 Freescale Semiconductor ...
Page 600: ...Advanced Technology Attachment ATA Freescale Semiconductor 23 25 ...
Page 601: ...Freescale Semiconductor 1 ...
Page 842: ...I2 C Interface Freescale Semiconductor 33 16 ...
Page 843: ...Freescale Semiconductor 1 ...
Page 921: ...Revision History A 6 Freescale Semiconductor ...