zkevm-docs/9-bitwise.markdown

-新增的子电路，专门处理 AND OR XOR BYTE 这些按位运算的指令。
+专门处理 AND OR XOR BYTE 这些按位运算的指令的子电路。在此电路内，位数长的整数被拆成字节，以字节为单位进行逻辑运算。
 
-TODO
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+## 设计
+
+### Witness、Column设计
+
+见代码
+
+```rust
+pub struct Row {
+    /// The operation tag, one of AND, OR, XOR
+    pub tag: Tag,
+    /// The byte value of operand 0
+    pub byte_0: U256,
+    /// The byte value of operand 1
+    pub byte_1: U256,
+    /// The byte value of operand 2
+    pub byte_2: U256,
+    /// The accumulation of bytes in one operation of operand 0
+    pub acc_0: U256,
+    /// The accumulation of bytes in one operation of operand 1
+    pub acc_1: U256,
+    /// The accumulation of bytes in one operation of operand 2
+    pub acc_2: U256,
+    /// The sum of bytes in one operation of operand 2, used to compute byte opcode
+    pub sum_2: U256,
+    /// The counter for one operation
+    pub cnt: U256,
+}
+```
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