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Texas Instruments TMS320C645X User Manual

Page 72

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Boot

Program

Host

Controller

Optional

I2C

EEPROM

DSP

ROM

1x RapidIO

SRIO Functional Description

2.3.12

Bootload Capability

2.3.12.1

Configuration

It is assumed that an external device will initiate the bootload data transfer and master the DMA interface.
Upon reset, the following sequence of events must occur:

1. DSP is placed in SRIO boot mode by HW mode pins.
2. Host takes DSP out of reset (POR or RST). The peripheral’s state machines and registers are reset.
3. Internal boot-strap ROM configures device registers, including SERDES, and DMA. DSP executes

internal ROM code to initialize SRIO.

Choice of 4 pin selectable configurations

Optionally, I2C boot can be used to configure SRIO

4. DSP executes idle instruction.
5. RapidIO ports send Idle control symbols to train PHYs.
6. Host enabled to explore system with RapidIO Maintenance packets.
7. Host identifies, enumerates and initializes the RapidIO device.
8. Host controller configures DSP peripherals through maintenance packets.

SRIO Device IDs are set for DSPs (either by pin strapping or by host manipulation)

9. Boot Code sent from host controller to DSP L2 memory base address via NWRITE.
10. DSP CPU is awakened by an interrupt such as a RapidIO DOORBELL packet.
11. Boot Code is executed and normal operation follows.

Figure 40. Bootload Operation

2.3.12.2

Bootload Data Movement

The system host is responsible for writing the bootload data into the DSP’s L2 memory. As such, bootload
is only supported using the Direct I/O model, and not the message passing model. Bootload data must be
sent in packets with explicit L2 memory addresses indicating proper destination within the DSP. As part of
the peripheral’s configuration, it should be set up to transfer the desired bootload program to the DSP's
memory through normal DMA bus commands.

2.3.12.3

Device Wakeup

Upon completion of the bootload data transfer, the system host issues a DOORBELL interrupt to the DSP.
The RapidIO peripheral processes this interrupt in a manner similar to that described in

Section 4

,

monitoring the DMA bus write-with-response commands to ensure that the data has been completely
transferred through the DMA. This interrupt wakes up the CPUs by pulling them out of their reset state.

The 16-bit data field of the DOORBELL packet should be configured to interrupt Core 0 by setting a
corresponding ICSR bit as described in

Figure 43

.

Serial RapidIO (SRIO)

72

SPRU976 – March 2006

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