SMJ320C40 Datasheet, PDF (4/62 Pages) Texas Instruments – DIGITAL SIGNAL PROCESSORS

SMJ320C40, TMP320C40
DIGITAL SIGNAL PROCESSORS
SGUS017H – OCTOBER 1993 – REVISED OCTOBER 2001
communication ports (continued)
D Separate 8-word-deep input and output FIFO buffers for processor-to-processor communication and I/O
D Automatic arbitration and handshaking for direct processor-to-processor connection
communication-port software reset (C40 silicon revision ≥ 5.0)
The input and output FIFO levels for a communication port can be flushed by writing at least two back-to-back
values to its communication-port software-reset address as specified in Table 1. This feature is not present in
C40 silicon revision < 5.0. This software reset flushes any word or byte already present in the FIFOs but it does
not affect the status of the communication-port pins. Figure 1 shows an example of
communication-port-software reset.
Table 1. Communication-Port Software-Reset Address
0
0x0100043
1
0x0100053
2
0x0100063
3
0x0100073
4
0x0100083
5
0x0100093
; –––––––––––––––––––––––––––––––––––––––––––––-–––;
; RESET1:Flush’s FIFO data for communication port 1;
; –––––––––––––––––––––––––––––––––––––––––––––-–––;
RESET1 push AR0
; Save registers
push R0
;
push RC
;
ldhi
or
flush: rpts
sti
rpts
010h,AR0
050h,AR0
1
R0,*+AR0(3)
10
; Set AR0 to base address of COM 1
;
; Flush FIFO data with back-to-back write
;
; Wait
nop
;
ldi *+AR0(0),R0 ; Check for new data from other port
and 01FE0h,R0
bnz flush
pop RC
;
;
; Restore registers
pop R0
;
pop AR0
;
rets
; Return
Figure 1. Example of Communication-Port-Software Reset
4
• POST OFFICE BOX 1443 HOUSTON, TEXAS 77251–1443