UPSD3254 STMICROELECTRONICS [STMicroelectronics], UPSD3254 Datasheet - Page 31

• Manufacturer Part Number: UPSD3254
• Description: Flash Programmable System Devices with 8032 Microcontroller Core
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

Figure 14. State Sequence in uPSD325X Devices
(XTAL2)
a. 1-Byte, 1-Cycle Instruction, e.g. INC A
b. 2-Byte, 1-Cycle Instruction, e.g. ADD A, adrs
c. 1-Byte, 2-Cycle Instruction, e.g. INC DPTR
d. 1-Byte, 2-Cycle MOVX Instruction
Osc.
p1
S1
S1
S1
S1
S1
Read opcode
Read opcode
Read opcode
Read opcode
(MOVX)
p2
p1
S2
S2
S2
S2
S2
p2
p1
S3
S3
S3
S3
S3
p2
p1
S4
S4
S4
S4
S4
Read next
opcode and
discard
Read 2nd
Byte
Read next
opcode and
discard
Read next
opcode and
discard
UPSD3254A, UPSD3254BV, UPSD3253B, UPSD3253BV
p2
p1
S5
S5
S5
S5
S5
Addr
p2
Access External Memory
p1
S6
S6
S6
S6
S6
p2
p1
S1
S1
S1
No ALE
Read next
opcode
Read next
opcode
Read next
opcode and
discard
No Fetch
p2
Data
p1
S2
S2
S2
p2
p1
S3
S3
S3
p2
p1
S4
S4
S4
Read next
opcode and
discard
No Fetch
p2
p1
S5
S5
S5
p2
p1
S6
S6
S6
p2
Read next
opcode
Read next
opcode
AI06822
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