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[](https://opensource.org/licenses/Apache-2.0) [](https://github.com/efabless/caravel_project_example/actions/workflows/user_project_ci.yml) [](https://github.com/efabless/caravel_project_example/actions/workflows/caravel_build.yml)
-| :exclamation: Important Note |
-|-----------------------------------------|
+# Jacaranda-8: 8bit CPU
+Jacaranda-8 is educational ISA for home-build CPU beginners. This project implements the microarchitecture: CHARLATAN which is a simple implementation of Jacaranda-8 ISA.The following table shows the specifications of this CPU.
-## Please fill in your project documentation in this README.md file
+
-Refer to [README](docs/source/index.rst#section-quickstart) for a quickstart of how to use caravel_user_project
+|item|value|
+|:---------:|:----------:|
+|microarchitecture|CHARLATAN|
+|data bus width|8bit|
+|instruction bus width|8bit|
+|memory address bus width|8bit|
+|architecture type|harvard architecture, RISC|
+|number of general purpose register|4|
+|I/O|memory mapped|
+|Interruption|enabled|
-Refer to [README](docs/source/index.rst) for this sample project documentation.
+|Instruction type|field|
+|----------------|-|
+|reg-imm load/store|op[3:0] imm[3:0]|
+|reg-reg mov|op[3:0] rd[1:0] rs[1:0]|
+|reg-reg cal|op[3:0] rd[1:0] rs[1:0]|
+|jump/branch|op[3:0] mode[1:0] rs[1:0]|
+|reg-mem load/store|op[3:0] rd[1:0] rs[1:0]|
+
+|registers|type|
+|---------|----|
+|pc|program counter|
+|flag|comparison flag|
+|r0|general purpose|
+|r1|general purpose|
+|r2|general purpose|
+|r3|general purpose/immediate load|
+
+|Number|Instruction name|mnemonic|7|6|5|4|3|2|1|0|pesudo code|
+|------|----------------|--------|-|-|-|-|-|-|-|-|-----------|
+|0|Move|mov rd, rs|0|0|0|0|rd_index[1]|rd_index[0]|rs_index[1]|rs_index[0]|rd[7:0] = rs[7:0], PC += 1|
+|1|Add|add rd, rs|0|0|0|1|rd_index[1]|rd_index[0]|rs_index[1]|rs_index[0]|rd[7:0] = rd[7:0] + rs[7:0], PC += 1|
+|2|Substruct|sub rd, rs|0|0|1|0|rd_index[1]|rd_index[0]|rs_index[1]|rs_index[0]|rd[7:0] = rd[7:0] - rs[7:0], PC += 1|
+|3|And|and rd, rs|0|0|1|1|rd_index[1]|rd_index[0]|rs_index[1]|rs_index[0]|rd[7:0] = rd[7:0] & rs[7:0], PC += 1|
+|4|Or|or rd, rs|0|1|0|0|rd_index[1]|rd_index[0]|rs_index[1]|rs_index[0]|rd[7:0] = rd[7:0] \| rs[7:0], PC += 1|
+|5|Not|not rd, rs|0|1|0|1|rd_index[1]|rd_index[0]|rs_index[1]|rs_index[0]|rd[7:0] = !rs[7:0], PC += 1|
+|6|Shift Left Logical|sll rd, rs|0|1|1|0|rd_index[1]|rd_index[0]|rs_index[1]|rs_index[0]|rd[7:0] = rd[7:0] << rs[7:0], PC += 1|
+|7|Shift Right Logical|srl rd, rs|0|1|1|1|rd_index[1]|rd_index[0]|rs_index[1]|rs_index[0]|rd[7:0] = rd[7:0] >> rs[7:0], PC += 1|
+|8|Shift Right Arithmetic|sra rd, rs|1|0|0|0|rd_index[1]|rd_index[0]|rs_index[1]|rs_index[0]|rd[7:0] = rd[7:0] >>> rs[7:0], PC += 1|
+|9|Compare|cmp rd, rs|1|0|0|1|rd_index[1]|rd_index[0]|rs_index[1]|rs_index[0]|flag = rd[7:0] == rs[7:0], PC += 1|
+|10|Jump equal|je rs|1|0|1|0|0|0|rs_index[1]|rs_index[0]|PC = flag ? rs[7:0] : PC += 1|
+|11|Jump|jmp rs|1|0|1|1|0|0|rs_index[1]|rs_index[0]|PC = rs[7:0]|
+|12|Load Immediate High|ldih imm|1|1|0|0|imm[3]|imm[2]|imm[1]|imm[0]|imm_register[7:4] = imm[3:0], PC += 1|
+|13|Load Immediate Low|ldil imm|1|1|0|1|imm[3]|imm[2]|imm[1]|imm[0]|imm_register[3:0] = imm[3:0], PC += 1|
+|14|Load|ld rd, rs|1|1|1|0|rd_index[1]|rd_index[0]|rs_index[1]|rs_index[0]|rd[7:0] = mem[rs[7:0]], PC += 1|
+|15|Store|st rd, rs|1|1|1|1|rd_index[1]|rd_index[0]|rs_index[1]|rs_index[0]|mem[rs[7:0]] = rd[7:0], PC += 1|
+|16|Interrupt Return|iret|1|0|1|1|0|1|0|0|PC = retaddr|
+
+## project build guide
+
+## Jacaranda-8 programming guide
+You can program your Jacaranda-8 machine code from the management SoC by Wishbone bus.
+
+|address|function|
+|:-----:|:-------|
+|0x3000_0000|IMEM_WRITE|
+|0x3000_0004|UART_CLK_FREQ|
+
+### IMEM_WRITE
+* bits[7:0] for data that will be contained in the instruction memory.
+* bits[15:8] for address that indicates address in the instruction memory.
+
+### UART_CLK_FREQ
+put board's clock frequency
+
+
+## Jacaranda MMapped I/O summary
+
+|address|description|note|
+|-------|-----------|----|
+|255|UART FLAG REGISTER 1(UFR1)||
+|254|UART FLAG REGISTER 2(UFR2)|read only|
+|253|UART TX DATA(UTD)||
+|252|UART RX DATA(URD)|read only|
+|251|GPIO OUT||
+|250|interrupt vector||
+|249|GPIO IN|read only|
