AM186ES Advanced Micro Devices, AM186ES Datasheet - Page 83

• Manufacturer Part Number: AM186ES
• Description: microcontrollers provide a low-cost/ high-performance solution for embedded system designers who wish to use the x86 architecture.
• Manufacturer: Advanced Micro Devices

Table 5-5
Table 5-6
PCS Address Ranges
Bits 6–4: Reserved—Set to 1.
Bit 3: Wait-State Value (R3)—If this bit is set to 0, the number of wait states from zero to
three is encoded in the R1–R0 bits. In this case, R1–R0 encodes from zero (00b) to three
(11b) wait states.
When R3 is set to 1, the four possible values of R1–R0 encode four additional wait-state
values as follows: 00b = 5 wait states, 01b = 7 wait states, 10b = 9 wait states, and 11b =
15 wait states. Table 5-6 shows the wait-state encoding.
PCS3–PCS0 Wait-State Encoding
Bit 2: Ready Mode (R2)—The R2 bit is used to configure the ready mode for the PCS3–
PCS0 chip selects. If R2 is set to 0, external ready is required. External ready is ignored
when R2 is set to 1. In each case, the processor also uses the value of the R3 and R1–R0
bits to determine the number of wait states to insert. The ready mode for PCS6–PCS5 is
configured through the MPCS register.
Bits 1–0: Wait-State Value (R1–R0)—The value of R3 and R1–R0 determines the number
of wait states inserted into a PCS3–PCS0 access. Up to 15 wait states can be inserted.
See the discussion of bit 3 (R3) for the wait-state encoding of R1–R0.
From zero to three wait states for the PCS6–PCS5 outputs are programmed through the
R1–R0 bits in the MPCS register.
PCS0
PCS1
PCS2
PCS3
Reserved N/A
PCS5
PCS6
PCS Line
R3
0
0
0
0
1
1
1
1
Low
Base Address
Base Address+256
Base Address+512
Base Address+768
Base Address+1280 Base Address+1535
Base Address+1536 Base Address+1791
R1
0
0
1
1
0
0
1
1
R0
0
1
0
1
0
1
0
1
Range
Wait States
Chip Select Unit
High
Base Address+255
Base Address+511
Base Address+767
Base Address+1023
N/A
15
0
1
2
3
5
7
9
5-13