TMS320F datasheet(59/389 Pages) TI

59 / 389 page

Status Registers ST0 and ST1

4-15

Central Processing Unit

4.5

Status Registers ST0 and ST1

The ’C24x has two status registers, ST0 and ST1, which contain status and

control bits. These registers can be stored to, and loaded from, data memory.

This allows the status of the machine to be saved and restored for subroutines.

The LST (load status register) instruction writes to ST0 and ST1, and the SST

(store status register) instruction reads from ST0 and ST1 (with the exception

of the INTM bit, which is not affected by the LST instruction). Many of the indi-

vidual bits of these registers can be set and cleared using the SETC and CLRC

instructions. For example, the sign-extension mode is set with SETC SXM and

cleared with CLRC SXM.

Figure 4–10 and Figure 4–11 show the organization of status registers ST0

and ST1, respectively. Several bits in the status registers are reserved; they

are always read as logic 1s. The other bits are described in alphabetical order

in Table 4–2.

Figure 4–10. Status Register ST0

ARP

OVM

1†

INTM

R/W–x

R/W–0

R/W–x

R/W–1

R/W–x

Note:

R = Read access; W = Write access; value following dash (–) is value after reset (x means value not affected by reset).

† This reserved bit is always read as 1. Writes have no effect on it.

Figure 4–11. Status Register ST1

ARB

CNF

SXM

1†

R/W–x

R/W–0

R/W–x

R/W–1

R/W–00

Note:

R = Read access; W = Write access; value following dash (–) is value after reset (x means value not affected by reset).

† These reserved bits are always read as 1s. Writes have no effect on them.

TMS320F Datasheet(PDF) 59 Page - Texas Instruments

TMS320F Datasheet(HTML) 59 Page - Texas Instruments

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL