SDIO Indirection Register for Memory Addressing
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Solution Overview
Problem
The existing SDIO communication standard is limited by a 17-bit address field, restricting the address range to 128 KB, which is insufficient for larger data transfers, such as those required for WiFi data packets, and previous solutions like chained lists of descriptors lack flexibility in address control and volume limitations.
Innovation Solution
The implementation of an indirection register that allows indirect addressing, enabling access to any memory region up to 1 MB within a 4 GB memory space, and can be configured by either the master or slave system for adaptability and security.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a 17-bit address field is used in SDIO commands, then the command structure remains simple and compatible with the standard, but the address range is limited to 128 KB which is insufficient for larger data transfers
Solution Approach 1:
The patent introduces an indirection register as an intermediary component between the command address field and the actual data memory. The command field (17 bits) selects an indirection register index, which in turn points to the actual data region in memory. This mediator enables indirect addressing, allowing the limited command field to access a much larger address space through the indirection register mechanism.
2Adaptability or versatility
If the address range is extended beyond 128 KB, then larger data transfers become possible, but the master device loses control over address range selection
Solution Approach 1:
The indirection register mechanism provides dynamic address range selection. The master device can programmatically configure which indirection register is selected and what address ranges they contain, allowing flexible adaptation to different data transfer needs. This dynamic configuration enables the master device to control and adjust the active address range based on the specific operation requirements.
Data Source
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AI summary
One aspect concerns a method of data communication between a slave device (SLV) and a master device (HST) according to a communication protocol (SDIO), the data being stored in a memory belonging to the slave device (SLV), the method comprising a generation by the master device of a command (CMD) provided by said communication protocol, and a use of a field of the command (RegAdd) in order to select an indirection register (DMAi_BAdd ; DMAi_Sz) belonging to the slave device and containing an address of a region of memory (MEM) containing the data.