DSP56857 datasheet(326/662 Pages) FREESCALE

326 / 662 page

5685X Digital Signal Controller User Manual, Rev. 4

12-26

Freescale Semiconductor

12.8 Register Descriptions (ESSI0_BASE = $1FFE20,

ESSI1_BASE = $1FFE00)

All registers are addressed by word. Byte accesses to the registers are not supported. Eight

registers are not accessible. Registers associated with the Enhanced SSI (ESSI) are delineated in

the Memory Chapter, Table 3-16 and Table 3-17.

12.8.1 ESSI Transmit Registers (STX0, STX1, STX2)

The ESSI Transmit Data (STX02) are write-only 16-bit registers. Data to be transmitted is written

to these registers. If the Transmit FIFO Registers are utilized, data is transferred from the STX02

registers to the Transmit FIFO Register as the FIFOs have available space. Otherwise, data written

to these registers is transferred to the Transmit Shift Register (STX02) whenever the transmit

FIFO feature is enabled. When the feature is enabled, the Transmit Shift Registers (TXSR02)

receive their values from these FIFO registers. Transmitted data is first-in-first-out. If the transmit

FIFO feature is not enabled, this register is bypassed and the contents of the Transmit Data

Registers (STX02) is transferred into the Transmit Shift Registers (TXSR02). When the Transmit

Interrupt Enable (TIE) bit in SCR2 register is set the DSC is interrupted when the level of data in

an enabled transmit FIFO falls below the selected threshold and the Transmit Data Register Empty

(TDE) bit in the ESSI Status Register (SSR) is set.

When both Transmit FIFO and Transmit Data Registers are full, any further write will overwrite

the content of the Transmit Data Registers (STX02).

Add.

Offset

98765

4321

STXCR

PSR

SRXCR

PSR

STSR

DUMMY REGISTER WRITTEN DURING INACTIVE TIME SLOTS (NETWORK MODE)

SFCSR

RFCNT

TFCNT

RFWM

TFWM

TSMA

TSMA [15:0]

TSMB

TSMB [31:16]

RSMA

RSMA [15:0]

RSMA

RSMB [31:16]

Read as 0

Reserved

Figure 12-11. ESSI Register Map Summary (Continued)

DSP56857 Datasheet(PDF) 326 Page - Freescale Semiconductor, Inc

DSP56857 Datasheet(HTML) 326 Page - Freescale Semiconductor, Inc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL