<?php
bit_breakout_start(4, "Mnemonic");
bit_breakout_hdr("xorfirst");
bit_breakout_bits_split("1000");
bit_breakout_bits(-1, "Number of first bit set in Op1 ^ Op2");
bit_breakout_hdr("rsb");
bit_breakout_bits_split("1001");
bit_breakout_bits(-1, "Rd <=-Op1 + Op2");
bit_breakout_hdr("bic");
bit_breakout_bits_split("1010");
bit_breakout_bits(-1, "Rd <= Op1 &~Op2");
bit_breakout_hdr("andxor");
bit_breakout_bits_split("1110");
bit_breakout_bits(-1, "Rd <= Op1 + Op2; used in conditional 'all set'");
bit_breakout_hdr("rsc");
bit_breakout_bits_split("1110");
bit_breakout_bits(-1, "Math mode: Rd <=-Op1 + Op2 - !C");
bit_breakout_end();
?>
The native ALU instruction is mapped to an internal ALU instruction first by mapping the ALU operation, the registers, and the conditional. If not extended then the conditional is derived in the standard way, and the registers are mapped in the standard way with the Rn specified in the instruction mapping both for Rn and Rd. If extended then the extended mappings are used.
<p>
The ALU op is mapped according to table:
<table>
<tr><th>ALU op<th>Internal instruction op</tr>
<tr><td>and<td>IAND</tr>
<tr><td>bic<td>IBIC</tr>
<?php
bit_breakout_start(32, "Transaction");
bit_breakout_hdr("Start");
bit_breakout_bits(19, "User data");
bit_breakout_bits(4, "(Target port)");
bit_breakout_bits(4, "(Length)");
bit_breakout_bits(4, "Target address");
bit_breakout_bits(1, "Single word");
bit_breakout_bits(-1, "Routing header word, bracketed items recommended but not required");
bit_breakout_hdr("Data*");
bit_breakout_bits(32, "User data");
bit_breakout_bits(-1, "Optional data words");
bit_breakout_hdr("Hold*");
bit_breakout_bits(32, "<i>Ignored</i>");
bit_breakout_bits(-1, "Pauses the transaction");
bit_breakout_hdr("Last");
bit_breakout_bits(32, "User data");
bit_breakout_bits(-1, "Optional last data word");
bit_breakout_end();
?>
A single word transaction is indicated by a Start transaction word
with bit 0 of its data set; a multi-word transaction is indicated by a
Start transaction word with bit 0 of its data clear, and it requires
zero or more data/hold words and a Last transaction word to follow it.
<?php
page_section("routing", "Routing");
?>
Routing is accomplished by looking at the target address bits in the
