SH7052 datasheet(378/919 Pages) RENESAS

378 / 919 page

352

10.3.12

Channel 10 Functions

Inter-Edge Measurement Function and Edge Input Cessation Detection Function:32-bit input

capture register 10A (ICR10A) and 32-bit output compare register 10A (OCR10A) in channel 10

unconditionally perform input capture and compare-match operations, respectively. These

registers are connected to 32-bit free-running counter TCNT10A.

When the corresponding bit is set in the timer start register (TSTR), the entire channel 10 starts

operating. ICR10A has an external input pin (TI10), and when an edge is input at this input pin,

ICR10A captures the TCNT10A value. At this time, TCNT10A is cleared to H'00000001. The

captured value is transferred to the read register (RLD10C) in the multiplied clock generation

block. By making the appropriate setting in the interrupt enable register (TIER), an interrupt

request can be sent to the CPU. This allows inter-edge measurement to be carried out.

When TCNT10A reaches the value set in OCR10A, a compare-match interrupt can be requested.

In this way it is possible to detect the cessation of edge input beyond the time set in OCR10A.

The input edge from TI10 is synchronized internally; the internal signal is AGCK. Noise

cancellation is possible for edges input at TI10 using the timer 10H (TCNT10H) input cancellation

function by setting the NCE bit in timer control register TCR10. When an edge is input at TI10,

TCNT10H starts and input is disabled until it reaches compare-match register NCR10.

Edge input operation without noise cancellation is shown in figure 10.26, edge input operation

with noise cancellation in figure 10.27, and TCNT10A capture operation and compare-match

operation in figure 10.28.

Pø

TI10

AGCK

After internal

synchronization 1

After internal

synchronization 2

AGCK operation

TCNT clock

When falling

edge is set

When rising

edge is set

When rising and falling

edges are set

Figure 10.26 Edge Input Operation (Without Noise Cancellation)

SH7052 Datasheet(PDF) 378 Page - Renesas Technology Corp