Prepare TTH
in memory for IVA MMU in SDRAM
Write an executable bootstrap
sequence in SDRAM
Reset
DSP ready for
autonomous boot
Initialize IVA MMU
Initialize time-critical entry in the
TLB IVA MMU
Enable IVA MMU
Configure L3 firewall to ensure IVA
read access to bootstrap code and
read/write access to IVA MMU
Write bootstrap address and boot mod
in the proper control module registers
Configure IVA clock rate and
power-management setting
Release IVA from reset
MMU
configuration
part
iva2-037
Public Version
IVA2.2 Subsystem Basic Programming Model
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NOTE:
Following Steps 1 through 8, the IVA2.2 boot sequence is identical to the autonomous
boot sequence. For information about the IVA2.2 boot sequence, see
IVA2.2 Boot.
Figure 5-26. IVA2 Boot Basic Programming Model
5.4.1.2.2 Autonomous Boot
On an OFF-to-ACTIVE transition (under MPU control or upon interrupt wakeup), the IVA2.2 subsystem is
released from reset.
After hardware configuration of values for DSP megamodule generic parameters, the IVA2.2 starts
fetching from the address 0x00000000 in ROM. The IVA2.2 must follow the (nonexhaustive) boot process:
1. Configure memory protection:
(a) Specify cache RAMs versus IDMA and DMA accesses.
(b) Define accessible L2 space (static shared L2 with the MPU/LCD).
2. Load the bootstrap code:
(a) Read the IVA_SYSC.
[31:12] BOOTLOADADDR bit field.
(b) Read the number of bootstrap words <NbOfWords> to transfer in the first word at the address
pointed to by BOOTLOADADDR.
(c) Transfer as many words as defined in <NbOfWords>.
3. Execute the bootstrap code.
NOTE:
This prepares the MMU for address translation of external accesses. In the case of a boot
upon interrupt wakeup, the MMU is restored to its exact context before the IVA2.2 is shut off,
if this context was saved correctly.
Only from this point can the IVA2.2 subsystem work with virtual addresses.
748
IVA2.2 Subsystem
SWPU177N – December 2009 – Revised November 2010
Copyright © 2009–2010, Texas Instruments Incorporated