28478G-18 Mindspeed Technologies, 28478G-18 Datasheet - Page 131

• Manufacturer Part Number: 28478G-18
• Description: Multichannel Synchronous Communications Controller 208-Pin BGA
• Manufacturer: Mindspeed Technologies

Specifications of 28478G-18

• Package: 208BGA
• Maximum Data Rate: 32768 Kbps
• Transmission Media Type: Wire
• Power Supply Type: Analog
• Typical Supply Current: 250 mA
• Typical Operating Supply Voltage: 3.3 V
• Minimum Operating Supply Voltage: 3 V
• Maximum Operating Supply Voltage: 3.6 V

6.3.2
For the Group Base Pointer the host must allocate a 2 kB bound memory segment for Channel Group 0. The value
calculated as the address for a Group Base Structure must be written into MUSYCC’s Group 0 Base Pointer
register using a PCI write cycle. After PCI configuration, this is a simple memory access by the host.
A service request does not exist to update this pointer in MUSYCC because all service requests reference this
pointer value to gain access to the shared memory resident group structure and the descriptors within it.
The components of the Group Base Pointer are listed in
Table 6-1.
6.3.3
28478-DSH-002-E
Descriptor
Pointer
#define TX_CHANNEL_CONFIG_DESCR_OFFSET..0x00000380
#define RX_time slot_MAP_OFFSET..........0x00000400
#define RX_SUBCHANNEL_MAP_OFFSET........0x00000480
#define RX_CHANNEL_CONFIG_DESCR_OFFSET..0x00000580
#define GLOBAL_CONFIG_DESCR_OFFSET......0x00000600
#define INT_QUEUE_DESCR_OFFSET..........0x00000604
#define INT_QUEUE_POINTER_OFFSET........0x00000604
#define INT_QUEUE_LENGTH_OFFSET.........0x00000608
#define GROUP_CONFIG_DESCR_OFFSET.......0x0000060C
#define MEMORY_PROTECT_DESCR_OFFSET.....0x00000610
#define MESSAGE_LENGTH_DESCR_OFFSET.....0x00000614
#define PORT_CONFIG_DESCR_OFFSET........0x00000618
#define SIZE_OF_GROUP_STRUCTURE 1564
#define GROUP_STR_BOUNDARY 2048
GroupStr0.pGroupBase = malloc( SIZE_OF_GROUP_STRUCTURE + GROUP_STR_BOUNDARY );
GroupStr0.pGroupBase = ( GroupStr0.pGroupBase + GROUP_STR_BOUNDARY ) &
/* group base pointer pointers must be a 2K byte aligned address */
/* above, there is enough space to first move forward 2K bytes, then */
/* lop off the 2K automatically. This will bring the pointer back */
/* to the original address or give us the next 2K byte boundary address */
/* IMPORTANT NOTE: be sure to save away the original pointer returned by the */
/* memory access routine as that same value will be required to free the space. */
/* must write directly into MUSYCC register */
*(MUSYCC_FUNC_0_BAR + GROUP_BASE_OFFSET) = GroupStr0.pGroupBase;
/* CLOCK activity indicators - read only, writes are ignored */
/* MPU control - assume EBUS is not used and default values are fine */
/* PORTMAP = 0, PORT 0 mapped to CHANNEL GROUP 0 */
GroupStr0.GlobalConfigDescr = 0x00000000;
Group
Base
Example—Components of Group Base Pointer
Group Base Pointer
Global Configuration Descriptor
~(GROUP_STR_BOUNDARY -1);
Pointer to a shared memory segment large enough for all
configuration descriptors for Channel Group 0.
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Mindspeed Technologies
Component of Descriptor
Table
6-1.
®
Return pointer from “malloc ( )” adjusted to a 2 kB
boundary.
Value of Components
Basic Operation
118