diff options
Diffstat (limited to 'rtl/core/control/psr.sv')
| -rw-r--r-- | rtl/core/control/psr.sv | 34 |
1 files changed, 31 insertions, 3 deletions
diff --git a/rtl/core/control/psr.sv b/rtl/core/control/psr.sv index 758b730..5767124 100644 --- a/rtl/core/control/psr.sv +++ b/rtl/core/control/psr.sv @@ -11,7 +11,8 @@ module core_control_psr alu_b, input psr_mode mode, - input ctrl_cycle next_cycle, + input ctrl_cycle cycle, + next_cycle, input logic issue, output logic psr, @@ -26,13 +27,31 @@ module core_control_psr output psr_mode reg_mode ); + word exception_spsr; + assign psr_wb = psr_saved ? spsr_rd : cpsr_rd; - assign psr_wr = final_restore_spsr ? spsr_rd : alu_b; - assign psr_write = next_cycle.issue && (final_psr_write || final_restore_spsr); //TODO: casos donde esto no es cierto assign reg_mode = mode; + always_comb begin + psr_write = 0; + + if(next_cycle.issue) + psr_write = final_psr_write || final_restore_spsr; + + if(cycle.escalate || cycle.exception) + psr_write = 1; + + if(cycle.escalate) + //TODO: otros modos, y además F (FIQ) no cambia siempre + psr_wr = {24'b0, 3'b110, `MODE_UND}; + else if(cycle.exception) + psr_wr = exception_spsr; + else + psr_wr = final_restore_spsr ? spsr_rd : alu_b; + end + always_ff @(posedge clk or negedge rst_n) if(!rst_n) begin psr <= 0; @@ -40,6 +59,7 @@ module core_control_psr psr_wr_flags <= 0; psr_wr_control <= 0; + exception_spsr <= 0; final_psr_write <= 0; final_restore_spsr <= 0; end else if(next_cycle.issue) begin @@ -50,6 +70,14 @@ module core_control_psr final_psr_write <= issue && dec.psr.write; final_restore_spsr <= issue && dec.psr.restore_spsr; + end else if(next_cycle.escalate) begin + psr_saved <= 0; + psr_wr_flags <= 0; + psr_wr_control <= 1; + exception_spsr <= cpsr_rd; + end else if(next_cycle.exception) begin + psr_saved <= 1; + psr_wr_flags <= 1; end else if(next_cycle.psr) psr <= 0; |