Bus master I / O cycles, which were introduced by the LPC bus specification, and ISA-style DMA including the 32-bit variant introduced by the LPC bus specification, are not present in eSPI . Therefore, bus master memory cycles are the only allowed DMA in this standard.
42.
The concern is that a finite machine can only have 2 number-of-bits-in-memory possible states-and that means that the machine must return to a previous state after at most 2 number-of-bits-in-memory cycles and therefore can never halt.
43.
A Memory Address Register Storage ( MARS ) core memory read, clear, or write operation took 1.5 �s and each write operation was automatically ( but not necessarily immediately ) preceded by a read or clear operation of the same " register ( s ) " during the 10 �s memory cycle.
44.
The term " reduced " in that phrase was intended to describe the fact that the amount of work any single instruction accomplishes is reduced at most a single data memory cycle compared to the " complex instructions " of CISC CPUs that may require dozens of data memory cycles in order to execute a single instruction.
45.
Six cycles of thin-film memory per core memory cycle and fast adder circuitry permitted memory address indexing within the current instruction core memory cycle and also modification of the index value ( the signed upper 18 bits were added to the lower 18 bits ) in the specified index register ( 16 were available ).
46.
Six cycles of thin-film memory per core memory cycle and fast adder circuitry permitted memory address indexing within the current instruction core memory cycle and also modification of the index value ( the signed upper 18 bits were added to the lower 18 bits ) in the specified index register ( 16 were available ).
47.
The magnetic core memory's cycle time was 5 microseconds ( corresponding roughly to a " clock speed " of 200 kilohertz ); consequently most arithmetic instructions took 10 microseconds ( 100, 000 operations per second ) because they used two memory cycles : one for the instruction, one for the operand data fetch.
48.
For example, a value in memory could be read with post-increment almost as quickly as it could be read; the hardware simply incremented the value between the read phase and the write phase of a single memory cycle ( perhaps signalling the memory controller to pause briefly in the middle of the cycle ).
49.
If a TLB hit takes 1 clock cycle, a miss takes 30 clock cycles, and the miss rate is 1 %, the effective memory cycle rate is an average of 1 ?0.99 + ( 1 + 30 ) ?0.01 = 1.30 ( 1.30 clock cycles per memory access ).
50.
This standard supports standard memory cycles with lengths of 1 byte to 4 kilobytes of data, short memory cycles with lengths of 1, 2, or 4 bytes that have much less overhead compared to standard memory cycles, and I / O cycles with lengths of 1, 2, or 4 bytes of data which are low overhead as well.
