Texas Instruments TMS320VC5402 - Manual (Page 17)

TMS320VC5402
FIXEDĆPOINT DIGITAL SIGNAL PROCESSOR
SPRS079E – OCTOBER 1998 – REVISED AUGUST 2000
17 POST OFFICE BOX 1443
•
HOUSTON, TEXAS 77251–1443
software-programmable wait-state generator (continued)
Table 2. Software Wait-State Register (SWWSR) Bit Fields
BIT RESET
FUNCTION
NO. NAME
RESET
VALUE
FUNCTION
15 XPA 0
Extended program address control bit. XPA is used in conjunction with the program space fields
(bits 0 through 5) to select the address range for program space wait states.
14–12 I/O 1
I/O space. The field value (0–7) corresponds to the base number of wait states for I/O space accesses
within addresses 0000–FFFFh. The SWSM bit of the SWCR defines a multiplication factor of 1 or 2 for
the base number of wait states.
11–9 Data 1
Upper data space. The field value (0–7) corresponds to the base number of wait states for external
data space accesses within addresses 8000–FFFFh. The SWSM bit of the SWCR defines a
multiplication factor of 1 or 2 for the base number of wait states.
8–6 Data 1
Lower data space. The field value (0–7) corresponds to the base number of wait states for external
data space accesses within addresses 0000–7FFFh. The SWSM bit of the SWCR defines a
multiplication factor of 1 or 2 for the base number of wait states.
5–3 Program 1
Upper program space. The field value (0–7) corresponds to the base number of wait states for external
program space accesses within the following addresses:
- XPA = 0: x8000 – xFFFFh
- XPA = 1: The upper program space bit field has no effect on wait states.
The SWSM bit of the SWCR defines a multiplication factor of 1 or 2 for the base number of wait
states.
2–0 Program 1
Program space. The field value (0–7) corresponds to the base number of wait states for external
program space accesses within the following addresses:
- XPA = 0: x0000–x7FFFh
- XPA = 1: 00000–FFFFFh
The SWSM bit of the SWCR defines a multiplication factor of 1 or 2 for the base number of wait
states.
The software wait-state multiplier bit of the software wait-state control register (SWCR) is used to extend the
base number of wait states selected by the SWWSR. The SWCR bit fields are shown in Figure 5 and described
in Table 3.
Reserved
1 15
R/W-0
SWSM
0
R/W-0
LEGEND: R = Read, W = Write
Figure 5. Software Wait-State Control Register (SWCR) [MMR Address 002Bh]
Table 3. Software Wait-State Control Register (SWCR) Bit Fields
PIN RESET
FUNCTION
NO. NAME
RESET
VALUE
FUNCTION
15–1 Reserved 0 These bits are reserved and are unaffected by writes.
0 SWSM 0
Software wait-state multiplier. Used to multiply the number of wait states defined in the SWWSR by a factor
of 1 or 2.
- SWSM = 0: wait-state base values are unchanged (multiplied by 1).
- SWSM = 1: wait-state base values are mulitplied by 2 for a maximum of 14 wait states.