diff options
| author | John Hauser <31252952+jhauser-us@users.noreply.github.com> | 2020-08-14 14:00:15 -0700 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2020-08-14 14:00:15 -0700 |
| commit | 5b5041e36ed0a902b6fca6e13d56966112fa843a (patch) | |
| tree | 793b6b9eacb8a5f1c733188739a1108d6eee6059 | |
| parent | 9ee57dfe71b884b85200b8470816e687301cfaf6 (diff) | |
| download | riscv-isa-manual-5b5041e36ed0a902b6fca6e13d56966112fa843a.zip riscv-isa-manual-5b5041e36ed0a902b6fca6e13d56966112fa843a.tar.gz riscv-isa-manual-5b5041e36ed0a902b6fca6e13d56966112fa843a.tar.bz2 | |
Improve table of conditions for explicit CSR read/write (#564)
| -rw-r--r-- | src/csr.tex | 33 |
1 files changed, 18 insertions, 15 deletions
diff --git a/src/csr.tex b/src/csr.tex index bac1c7b..266e02a 100644 --- a/src/csr.tex +++ b/src/csr.tex @@ -100,30 +100,33 @@ any read side effects regardless of {\em rd} and {\em rs1} fields. \begin{table} \centering - \begin{tabular}{|l|r|r|c|c|} + \begin{tabular}{|l|c|c|c|c|} \hline \multicolumn{5}{|c|}{Register operand} \\ \hline - Instruction & rd & rs1 & read CSR? & write CSR? \\ + Instruction & \textit{rd} is \texttt{x0} + & \textit{rs1} is \texttt{x0} + & Reads CSR & Writes CSR \\ \hline - CSRRW & {\tt x0} & - & no & yes \\ - CSRRW & !{\tt x0} & - & yes & yes \\ - CSRR{S/C} & - & {\tt x0} & yes & no \\ - CSRR{S/C} & - & !{\tt x0} & yes & yes \\ + CSRRW & Yes & -- & No & Yes \\ + CSRRW & No & -- & Yes & Yes \\ + CSRRS/CSRRC & -- & Yes & Yes & No \\ + CSRRS/CSRRC & -- & No & Yes & Yes \\ \hline \multicolumn{5}{|c|}{Immediate operand} \\ \hline -Instruction & rd & uimm & read CSR? & write CSR? \\ + Instruction & \textit{rd} is \texttt{x0} + & \textit{uimm}$=$0 + & Reads CSR & Writes CSR \\ + \hline + CSRRWI & Yes & -- & No & Yes \\ + CSRRWI & No & -- & Yes & Yes \\ + CSRRSI/CSRRCI & -- & Yes & Yes & No \\ + CSRRSI/CSRRCI & -- & No & Yes & Yes \\ \hline - CSRRWI & {\tt x0} & - & no & yes \\ - CSRRWI & !{\tt x0} & - & yes & yes \\ - CSRR{S/C}I & - & 0 & yes & no \\ - CSRR{S/C}I & - & !0 & yes & yes \\ - \hline \end{tabular} - \caption{Table showing whether a CSR instruction reads or writes a - given CSR. The CSRRS and CSRRC instructions have same behavior so - are shown as CSRR{S/C} in Table.} + \caption{Conditions determining whether a CSR instruction reads or writes + the specified CSR.} \label{tab:csrsideeffects} \end{table} |