7-12
DSP56309UM/D MOTOROLA
Enhanced Synchronous Serial Interface (ESSI)
ESSI Programming Model
Note:
The combination PSR = 1 and PM[7:0] = $00 (dividing F
core
by 2) can cause
synchronization problems and should not be used.
7.4.1.4
CRA Frame Rate Divider Control DC[4:0] Bits 16Ð12
The values of the DC[4:0] bits control the divide ratio for the programmable frame rate
dividers used
to generate the frame clocks. In network mode, this ratio can be
interpreted as the number of words per frame minus one. In normal mode, this ratio
determines the word transfer rate.
The divide ratio can range from 1 to 32 (DC = 00000 to 11111) for normal mode and 2 to
32 (DC = 00001 to 11111) for network mode. A divide ratio of one (DC = 00000) in
network mode is a special case known as on-demand mode. In normal mode, a divide
ratio of one (DC = 00000) provides continuous periodic data word transfers. A bit-length
frame sync must be used in this case and is selected by setting the FSL[1:0] bits in the
CRA to (01). Both the hardware RESET signal and the software RESET instruction clear
DC[4:0].
The ESSI frame sync generator functional diagram is shown in
Figure 7-9
ESSI Clock Generator Functional Block Diagram
SCn0
SCKn
CRB(SCD0)
CRB(SCKD)
CRB(SYN) = 1
SCD0 = 0
RCLOCK
TCLOCK
Internal Bit Clock
SYN = 1
CRA(WL2:0)
RX Shift Register
TX Shift Register
/1 or /8
/1 to /256
F
CORE
RX
Word
Clock
SYN = 0
SCD0 = 1
Note: 1. F
CORE
is the DSP56300 Core internal
clock frequency.
2. ESSI internal clock range:
min = F
OSC
/4096
max = F
OSC
/4
3. ÔnÕ in signal name is ESSI # (0 or 1)
AA0679
Sync:
TX #1, or
Async:
RX clk
Sync:
TX/RX clk
Async:
TX clk
0
0
0
255
CRA(PSR)
CRA(PM7:0)
/8, /12, /16, /24, /32
1
2
3
4,5
Flag0 Out
(Sync Mode)
CRB(OF0)
CRB(TE1)
TX #1
Flag0 In
(Sync Mode)
SSISR(IF0)
1
SYN = 0
0
/8, /12, /16, /24, /32
1
2
3
4,5
/2
CRA(WL2:0)
TX
Word
Clock
Flag0
(Opposite
from SSI)
or
Summary of Contents for DSP56309
Page 25: ...xxii DSP56309UM D MOTOROLA Figure D 25 Port E Registers PCRE PRRE PDRE D 39 ...
Page 30: ...MOTOROLA DSP56309UM D 1 1 SECTION 1 DSP56309 OVERVIEW ...
Page 47: ...1 18 DSP56309UM D MOTOROLA DSP56309 Overview DSP56309 Architecture Overview ...
Page 48: ...MOTOROLA DSP56309UM D 2 1 SECTION 2 SIGNAL CONNECTION DESCRIPTIONS ...
Page 85: ...2 38 DSP56309UM D MOTOROLA Signal Connection Descriptions OnCE JTAG Interface ...
Page 86: ...MOTOROLA DSP56309UM D 3 1 SECTION 3 MEMORY CONFIGURATION ...
Page 104: ...MOTOROLA DSP56309UM D 4 1 SECTION 4 CORE CONFIGURATION ...
Page 124: ...MOTOROLA DSP56309UM D 5 1 SECTION 5 GENERAL PURPOSE I O ...
Page 125: ...5 2 DSP56309UM D MOTOROLA General Purpose I O 5 1 INTRODUCTION 5 3 5 2 PROGRAMMING MODEL 5 3 ...
Page 128: ...MOTOROLA DSP56309UM D 6 1 SECTION 6 HOST INTERFACE HI08 ...
Page 166: ...MOTOROLA DSP56309UM D 7 1 SECTION 7 ENHANCED SYNCHRONOUS SERIAL INTERFACE ESSI ...
Page 212: ...MOTOROLA DSP56309UM D 8 1 SECTION 8 SERIAL COMMUNICATION INTERFACE SCI ...
Page 241: ...8 30 DSP56309UM D MOTOROLA Serial Communication Interface SCI GPIO Signals and Registers ...
Page 242: ...MOTOROLA DSP56309UM D 9 1 SECTION 9 TRIPLE TIMER MODULE ...
Page 269: ...9 28 DSP56309UM D MOTOROLA Triple Timer Module Timer Operational Modes ...
Page 270: ...MOTOROLA DSP56309UM D 10 1 SECTION 10 ON CHIP EMULATION MODULE ...
Page 302: ...MOTOROLA DSP56309UM D 11 1 SECTION 11 JTAG PORT ...
Page 369: ...C 22 DSP56309UM D MOTOROLA DSP56309 BSDL Listing ...
Page 370: ...MOTOROLA DSP56309UM D D 1 APPENDIX D PROGRAMMING REFERENCE ...
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