IS200ISBEH1ABC控制卡件,脉冲输入卡件
字CR8的脉冲串图3-11显示了使用八拍递增脉冲串的写入传输。图3-11八拍递增脉冲串此脉冲串使用半字传输，因此地址增加2。因为脉冲串是递增的，所以地址继续递增超过16字节地址边界。未定义长度突发，INCR图3-12显示了未定义长度的递增突发。图3-12未定义长度突发Fi 15 ARM Limited或其附属公司。保留所有权利。3-39 ID102715非机密3.6等待传输如果从属设备需要更多时间提供或采样数据，则使用HREADYOUT插入等待状态。在等待的传输过程中，主机被限制为可以对传输类型和地址进行哪些更改。以下章节描述了这些限制：•等待状态期间传输类型的变化。•第3-42页等待状态期间的地址更改。3.6.1等待状态期间的传输类型更改当从设备请求等待状态时，主设备不得更改传输类型，除非：•IDLE传输。•第3-40页上的BUSY传输，固定长度突发。•BUSY传输，第3-41页未定义长度突发。IDLE传输在等待传输期间，允许主机将传输类型从IDLE更改为NONSEQ。当HTRANS传输类型更改为NONSEQ时，主机必须保持HTRANS恒定，直到HREADY为HIGH。图3-13显示了SINGLE突发的等待传输，传输类型从IDLE变为NONSEQ。图3-13等待传输，IDLE到NONSEQ在图3-13:T0-T1中，主机向地址a发起一个SINGLE突发。T1-T2主机向地址Y插入一个IDLE传输。从机插入一个等待状态，HREADYOUT=LOW。T2-T3主机向地址Z插入一个IDLE传输。T3-T4主机将传输类型更改为NONSEQ，并启动向地址B的INCR4传输。T4-T6如果HREADY LOW，主机必须保持HTRANS恒定。T5-T6到地址A的单脉冲串以HREADY HIGH结束，并且主机开始到地址B的第一个节拍。T6-T7到地址B INCR4传输的第一个拍完成，并且主机启动到地址B+4的下一个节拍。HADDR[31:0]A HCLK Y HBURST[2:0]单HREADY B B+4 HRDATA[31:0]INCR4 HTRANS[1:0]NONSEQ IDLE NONSEQ数据（A）T0 T1 T2 T3 T4 T6 T7数据（B）INCR4 IDLE Z 3传输3.6等待传输3-40版权所有©2001、2006、2010、2015 ARM Limited或其附属公司。保留所有权利。ARM IHI 0033B.b非机密ID102715 BUSY传输，固定长度突发在等待传输固定长度突发期间，允许主机将传输类型从BUSY更改为SEQ。当HTRANS传输类型更改为SEQ时，主机必须保持HTRANS恒定，直到HREADY为HIGH。注意：由于BUSY传输只能在脉冲串的连续拍之间插入，因此这不适用于SINGLE脉冲串。因此，这种情况适用于以下突发类型：•INCR4，
burst of word CR8 Figure 3-11 shows a write transfer using an eight-beat incrementing burst. Figure 3-11 Eight-beat incrementing burst This burst uses halfword transfers, therefore the addresses increase by two. Because the burst is incrementing, the addresses continue to increment beyond the 16-byte address boundary. Undefined length bursts, INCR Figure 3-12 shows incrementing bursts of undefined length. Figure 3-12 Undefined length bursts Fi 15 ARM Limited or its affiliates. All rights reserved. 3-39 ID102715 Non-Confidential 3.6 Waited transfers Slaves use HREADYOUT to insert wait states if they require more time to provide or sample the data. During a waited transfer, the master is restricted to what changes it can make to the transfer type and address. These restrictions are described in the following sections: • Transfer type changes during wait states. • Address changes during wait states on page 3-42. 3.6.1 Transfer type changes during wait states When the slave is requesting wait states, the master must not change the transfer type, except as described in: • IDLE transfer. • BUSY transfer, fixed length burst on page 3-40. • BUSY transfer, undefined length burst on page 3-41. IDLE transfer During a waited transfer, the master is permitted to change the transfer type from IDLE to NONSEQ. When the HTRANS transfer type changes to NONSEQ the master must keep HTRANS constant, until HREADY is HIGH. Figure 3-13 shows a waited transfer for a SINGLE burst, with a transfer type change from IDLE to NONSEQ. Figure 3-13 Waited transfer, IDLE to NONSEQ In Figure 3-13: T0-T1 The master initiates a SINGLE burst to address A. T1-T2 The master inserts one IDLE transfer to address Y. The slave inserts a wait state with HREADYOUT = LOW. T2-T3 The master inserts one IDLE transfer to address Z. T3-T4 The master changes the transfer type to NONSEQ and initiates an INCR4 transfer to address B. T4-T6 With HREADY LOW, the master must keep HTRANS constant. T5-T6 SINGLE burst to address A completes with HREADY HIGH and the master starts the first beat to address B. T6-T7 First beat of the INCR4 transfer to address B completes and the master starts the next beat to address B+4. HADDR[31:0] A HCLK Y HBURST[2:0] SINGLE HREADY B B+4 HRDATA[31:0] INCR4 HTRANS[1:0] NONSEQ IDLE NONSEQ SEQ Data (A) T0 T1 T2 T3 T4 T5 T6 T7 Data (B) INCR4 IDLE Z 3 Transfers 3.6 Waited transfers 3-40 Copyright © 2001, 2006, 2010, 2015 ARM Limited or its affiliates. All rights reserved. ARM IHI 0033B.b Non-Confidential ID102715 BUSY transfer, fixed length burst During a waited transfer for a fixed length burst, the master is permitted to change the transfer type from BUSY to SEQ. When the HTRANS transfer type changes to SEQ the master must keep HTRANS constant, until HREADY is HIGH. Note Because BUSY transfers must only be inserted between successive beats of a burst, this does not apply to SINGLE bursts. Therefore this situation applies to the following burst types: • INCR4,
