Essi Mode Select (Mod) Crb Bit 13; Figure 7-17 Crb Syn Bit Operation - Motorola DSP56305 User Manual

Enhanced Synchronous Serial Interface (ESSI)
ESSI Programming Model
7.4.2.12

ESSI Mode Select (MOD) CRB Bit 13

MOD selects the operational mode of the ESSI (see Figure 7-18). When MOD is cleared,
the Normal mode is selected; when MOD is set, the Network mode is selected. In the
Normal mode, the frame rate divider determines the word transfer rate: one word is
transferred per frame sync during the frame sync time slot. In Network mode, a word
may be transferred every time slot. For more details, see Section 7.5. Either a hardware
reset signal or a software reset instruction will clear MOD.
External Transmit Clock
SCK
Internal Clock
ESSI Bit
Clock
External Receive Clock
SC0
NOTE: Transmitter and receiver may have different clocks and frame syncs.
External Clock
SCK
Internal Clock
ESSI Bit
Clock
NOTE: Transmitter and receiver may have the same clock frame syncs.
7-26
Asynchronous (SYN = 0)
Transmitter
Clock
Clock
RECEIVER
SYNCHRONOUS (SYN = 1)
Transmitter
Clock
Clock
Receiver

Figure 7-17 CRB SYN Bit Operation

DSP56305 User's Manual
STD
Frame
SYNC
External Transmit Frame SYNC
Internal Frame SYNC
External Receive Frame SYNC
Frame
SYNC
SRD
STD
Frame
SYNC
External Frame SYNC
Internal Frame SYNC
Frame
SYNC
SRD
SC2
SC1
SC2
AA0682
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