i8237x2

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Provided by: 8237x2
Class Hierarchy: conf-object → log-object → i8237x2
Interfaces Implemented: log_object, io_memory
Description: The 8237x2 device implements the functionality of two cascaded 8237 DMA controllers. The 8237x2 supplies 7 dma channels that other devices can use for direct transfers to and from physical memory. The channel to use should be set in the device requesting DMA transfers. The 8237x2 exports two functions for reading and writing data. Limitation: Most registers in the 8237x2 device change hardware specific parameters. These do nothing in the 8237x2. Memory-to-Memory DMA transfers are not supported. The verify transfer type is not supported. Transfer delays are not modelled correctly, all transfers are completed in the same cycle as they are initiated by the device. Software initiated DMA requests are not supported.

Attributes inherited from class conf-object

attributes, classname, component, iface, name, object_id, queue

Attributes inherited from class log-object

access_count, log_buffer, log_buffer_last, log_buffer_size, log_group_mask, log_groups, log_level, log_type_mask

Attribute List

auto_init: Optional attribute; read/write access; type: unknown type.
(0|1, 0|1, 0|1, 0|1), (0|1, 0|1, 0|1, 0|1) If set re-initialize registers at terminal count.

base_addr: Optional attribute; read/write access; type: unknown type.
((a1, a2, a3, a4), (b1, b2, b3, b4)) The base address register for both chips' 4 DMA channels.

base_count: Optional attribute; read/write access; type: unknown type.
((a1, a2, a3, a4), (b1, b2, b3, b4)) The base count register.

current_addr: Optional attribute; read/write access; type: unknown type.
((a1, a2, a3, a4), (b1, b2, b3, b4)) The current address register. a1 - a4 are addresses of the first chip's 4 DMA channels' and b1 - b4 are for the second chip.

current_count: Optional attribute; read/write access; type: unknown type.
((a1, a2, a3, a4), (b1, b2, b3, b4)) The current count register.

dec_address: Optional attribute; read/write access; type: unknown type.
(0|1, 0|1, 0|1, 0|1), (0|1, 0|1, 0|1, 0|1) If set decrement addresses on transfers instead of increment. Per channel.

disabled: Optional attribute; read/write access; type: unknown type.
(0|1,0|1) If the chips are disabled or enabled.

dma_mode: Optional attribute; read/write access; type: unknown type.
((a1, a2, a3, a4), (b1, b2, b3, b4)) DMA mode 0 (demand), 1 (single), 2 (block), 3 (cascade) for all channels.

dma_type: Optional attribute; read/write access; type: unknown type.
((a1, a2, a3, a4), (b1, b2, b3, b4)) DMA type 0 (verify), 1 (write), 2 (read), 3 (illegal) for all channels.

extra_page_addr: Optional attribute; read/write access; type: unknown type.
((a1, a2, a3, a4), (b1, b2, b3, b4)) Extra page address registers. These registers have no function in the device.

flip_flop: Optional attribute; read/write access; type: unknown type.
(hi, lo) hi/lo byte access selector.

mask: Optional attribute; read/write access; type: unknown type.
(0|1, 0|1, 0|1, 0|1), (0|1, 0|1, 0|1, 0|1) Which channels are disables/enabled.

memory: Required attribute; read/write access; type: unknown type.
The physical memory to connect the DMA device to.

page_addr: Optional attribute; read/write access; type: unknown type.
((a1, a2, a3, a4), (b1, b2, b3, b4)) The 64k/128k page that DMA is relative.

page_size: Optional attribute; read/write access; type: unknown type.
(page-size1, page-size2) Page size for the controllers. 64k or 128k.

request: Optional attribute; read/write access; type: unknown type.
((a1, a2, a3, a4), (b1, b2, b3, b4)) The request register.

tc: Optional attribute; read/write access; type: unknown type.
(0|1, 0|1, 0|1, 0|1), (0|1, 0|1, 0|1, 0|1) Bit set on terminal count (TC) for a DMA channel.

Commands defined by interface log_object

log, log-group, log-level, log-size, log-type

Commands

info	print information about the device
status	print status of the device

<i8237x2>.info
Synopsis: <i8237x2>.info
Description: Print detailed information about the configuration of the device.

<i8237x2>.status
Synopsis: <i8237x2>.status
Description: Print detailed information about the current status of the device.

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