SPRUIY2 November 2024 F29H850TU , F29H859TU-Q1
When Dx registers are written in E1 and any pending instruction scheduled to write Dx in E2 or E3 causes a pipeline protection stall. This is shown in Table 4-9.
Register Sources | Pipeline Phase | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
D2 | R1 | R2 | R3 | E1 | E2 | E3 | E4 | E5 | E6 | |
Pipeline phase in register resource is read | ||||||||||
Dx | Yes | Yes | ||||||||
Pipeline phase in register resource is written | ||||||||||
Dx | Yes | Yes | Yes |
Dx Write Scheduled in E3 and Dx Read in E1 Phase of Pipeline is an example of Dx write scheduled in E3 and Dx is read in E1 phase of pipeline.
CRC D3, D2, D0, D1 ; CRC, 3 cycle instructon, Write in E3
ST.32 *A3, D3 ; Store D3, Read in E1
Table 4-10 is the pipeline diagram for the sequence in Dx Write Scheduled in E3 and Dx Read in E1 Phase of Pipeline. ST.32 is held in D2 for 2 cycle such that ST.32 enters E1 phase of pipeline when D3 is updated with CRC. This makes sure of order execution.
Cycle | Pipeline Phase | D0 Register | ||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
D2 | R1 | R2 | R3 | E1 | E2 | E3 | E4 | E5 | E6 | |||
1 | CRC | |||||||||||
2 | ST.32 | CRC | ||||||||||
3 | ST.32 | PROT | CRC | |||||||||
4 | ST.32 | PROT | PROT | CRC | ||||||||
5 | Instr 1 | ST.32 | PROT | PROT | CRC | |||||||
6 | Instr 2 | Instr 1 | ST.32 | PROT | PROT | CRC | D3=CRC | |||||
7 | Instr 3 | Instr 2 | Instr 1 | ST.32 | PROT | PROT | CRC | |||||
8 | Instr 4 | Instr 3 | Instr 2 | Instr 1 | ST.32 | PROT | PROT | CRC | ||||
9 | Instr 5 | Instr 4 | Instr 3 | Instr 2 | Instr 1 | ST.32 | PROT | PROT |