ATM Pace Control
MPC885 PowerQUICC Family Reference Manual, Rev. 2
Freescale Semiconductor
40-3
Figure 40-2. APC Control: PTP Queue and Scheduling Table Combination
40.1.1
APC Implementation
The APC is based on a dynamic scheduling table that contains pointers (implemented as channel numbers)
to the active channels. The rate at which the table scan encounters a channel number in the scheduling table
determines the transmit rate for that particular channel.
Each APC priority level’s scheduling table consists of an array of half-word channel numbers, and two
scan pointers (APCT_PTRx and APCT_SPTRx). Each table entry represents a time slot in which the
number of cells specified by the parameter NCITS are sent. During initialization, each entry of the APC
scheduling table should be programmed with 0xFFFF, which is reserved as the invalid channel number.
Issuing the
TRANSMIT
ACTIVATE
CHANNEL
command to the CPM causes a channel’s number to be inserted
into the APC scheduling table at the entry pointed to by the table scan pointer (APCT_PTRx).
Periodic timeouts of the APC timer activate the APC algorithm and cause the real-time scheduling table
scan pointer (APCT_PTRx) to advance one entry. Each time APCT_PTRx steps to the next entry in the
table, the APC reads each new channel number and schedules it again for a future time slot, according to
the APC pace parameter in each channel’s TCT.
Counter
APC scheduling table
Counter
APC scheduling table
APC Timer
Request (timer expiration)
PHY Transmit queue
Transmitter
ATM port to port
(PTP) queueing
APC control
Priority
Priority
level 1
level 2
Counter
APC scheduling table
Priority
level n
Содержание PowerQUICC MPC870
Страница 1: ...MPC885 PowerQUICC Family Reference Manual Supports MPC885 MPC880 MPC875 MPC870 MPC885RM Rev 2 04 2006 ...
Страница 98: ...MPC885 PowerQUICC Family Reference Manual Rev 2 I 4 Freescale Semiconductor ...
Страница 118: ...MPC885 Overview MPC885 PowerQUICC Family Reference Manual Rev 2 1 20 Freescale Semiconductor ...
Страница 158: ...The MPC8xx Core MPC885 PowerQUICC Family Reference Manual Rev 2 3 18 Freescale Semiconductor ...
Страница 192: ...MPC885 Instruction Set MPC885 PowerQUICC Family Reference Manual Rev 2 5 22 Freescale Semiconductor ...
Страница 242: ...Instruction and Data Caches MPC885 PowerQUICC Family Reference Manual Rev 2 7 30 Freescale Semiconductor ...
Страница 288: ...MPC885 PowerQUICC Family Reference Manual Rev 2 III 4 Freescale Semiconductor ...
Страница 416: ...External Bus Interface MPC885 PowerQUICC Family Reference Manual Rev 2 13 42 Freescale Semiconductor ...
Страница 440: ...Clocks and Power Control MPC885 PowerQUICC Family Reference Manual Rev 2 14 24 Freescale Semiconductor ...
Страница 554: ...MPC885 PowerQUICC Family Reference Manual Rev 2 V 6 Freescale Semiconductor ...
Страница 606: ...SDMA Channels and IDMA Emulation MPC885 PowerQUICC Family Reference Manual Rev 2 19 20 Freescale Semiconductor ...
Страница 738: ...SCC Asynchronous HDLC Mode and IrDA MPC885 PowerQUICC Family Reference Manual Rev 2 25 16 Freescale Semiconductor ...
Страница 780: ...SCC Ethernet Mode MPC885 PowerQUICC Family Reference Manual Rev 2 27 24 Freescale Semiconductor ...
Страница 794: ...SCC Transparent Mode MPC885 PowerQUICC Family Reference Manual Rev 2 28 14 Freescale Semiconductor ...
Страница 848: ...Serial Peripheral Interface SPI MPC885 PowerQUICC Family Reference Manual Rev 2 30 18 Freescale Semiconductor ...
Страница 882: ...Universal Serial Bus USB MPC885 PowerQUICC Family Reference Manual Rev 2 31 34 Freescale Semiconductor ...
Страница 944: ...Parallel I O Ports MPC885 PowerQUICC Family Reference Manual Rev 2 34 26 Freescale Semiconductor ...
Страница 956: ...CPM Interrupt Controller MPC885 PowerQUICC Family Reference Manual Rev 2 35 12 Freescale Semiconductor ...
Страница 1004: ...Buffer Descriptors and Connection Tables MPC885 PowerQUICC Family Reference Manual Rev 2 37 30 Freescale Semiconductor ...
Страница 1022: ...ATM Parameter RAM MPC885 PowerQUICC Family Reference Manual Rev 2 38 18 Freescale Semiconductor ...
Страница 1068: ...ATM Pace Control MPC885 PowerQUICC Family Reference Manual Rev 2 40 22 Freescale Semiconductor ...
Страница 1090: ...UTOPIA Interface MPC885 PowerQUICC Family Reference Manual Rev 2 43 8 Freescale Semiconductor ...
Страница 1120: ...AAL2 Implementation MPC885 PowerQUICC Family Reference Manual Rev 2 44 30 Freescale Semiconductor ...
Страница 1162: ...Fast Ethernet Controller FEC MPC885 PowerQUICC Family Reference Manual Rev 2 45 40 Freescale Semiconductor ...
Страница 1172: ...SEC Lite Overview MPC885 PowerQUICC Family Reference Manual Rev 2 46 8 Freescale Semiconductor ...
Страница 1176: ...SEC Lite Address Map MPC885 PowerQUICC Family Reference Manual Rev 2 47 4 Freescale Semiconductor ...
Страница 1214: ...SEC Lite Execution Units MPC885 PowerQUICC Family Reference Manual Rev 2 48 38 Freescale Semiconductor ...
Страница 1312: ...Byte Ordering MPC885 PowerQUICC Family Reference Manual Rev 2 A 8 Freescale Semiconductor ...
Страница 1313: ...MPC885 PowerQUICC Family Reference Manual Rev 2 Freescale Semiconductor B 1 Appendix B Serial Communications Performance TBD ...
Страница 1314: ...Serial Communications Performance MPC885 PowerQUICC Family Reference Manual Rev 2 B 2 Freescale Semiconductor ...
Страница 1320: ...Register Quick Reference Guide MPC885 PowerQUICC Family Reference Manual Rev 2 C 6 Freescale Semiconductor ...
Страница 1336: ...MPC885 PowerQUICC Family Reference Manual Rev 2 D 16 Freescale Semiconductor ...
Страница 1358: ...MPC885 PowerQUICC Family Reference Manual Rev 2 D 38 Freescale Semiconductor ...
Страница 1370: ...MPC880 MPC885 PowerQUICC Family Reference Manual Rev 2 E 4 Freescale Semiconductor ...
Страница 1384: ...Serial ATM Scrambling Reception and SI Programming MPC885 PowerQUICC Family Reference Manual Rev 2 H 6 Freescale Semiconductor ...
Страница 1386: ...Revision History MPC885 PowerQUICC Family Reference Manual Rev 2 I 2 Freescale Semiconductor ...