ZPSD511B1C15J STMicroelectronics, ZPSD511B1C15J Datasheet - Page 81

• Manufacturer Part Number: ZPSD511B1C15J
• Manufacturer: STMicroelectronics

Specifications of ZPSD511B1C15J

• Operating Temperature (max): 70C
• Operating Temperature (min): 0C
• Operating Temperature Classification: Commercial
• Mounting: Surface Mount
• Lead Free Status / RoHS Status: Supplier Unconfirmed

Counter/Timer
Operation
(Cont.)
78
PSD5XX Family
Figure 41. Timing Relationship Between CLKIN and the TC Signal.
NOTES: 1. Overflow occurs when a counter value changes from FFFFh to 0000h during incrementing.
9.6.1.8 Counter/Timer Clock Input
All Counter/Timers 0 through 3 have a common clock source. The Counter/Timers are
clocked from the output of a highly flexible and high resolution Divisor unit. The Divisor’s
input is the external Clock input pin. The Divisor DIV is a number in the range of
4
Figure 42 details the PSD5XX Counter clock generation.
The Counter/Timer CLOCK input
=
where DIV = N
The value of K depends on the Scale-Bit (Bit 0 in the Global Command Register) in the
“Global Command Register” , K = 8 when Scale-Bit is set to 1 and K = 1 when Scale-Bit is
set to 0. DLCY is the number of Delay Cycles in the range of 0
Delay Cycle Register. The fastest clock to service the Counter/Timer is = (Clock input / 4).
The maximum External Clock input value is 28 MHz and the fastest internal count frequency
is 7.0 MHz, i.e., a resolution of 143 ns. (Higher resolution can be achieved by using in
conjunction with GPLD macrocells). The default value of DIV is 4 (following a reset both K
and DLCY contain zeroes).
9.6.1.7 Terminal Counts (TCs)
The terminal counts (TC0 – TC3) generated by the Counter/Timers are made available
at Port E as outputs or as feedbacks to the ZPLD. Refer to Table 27a for pin assignments.
The terminal counts can be used to concatenate the 16-bit Counter/Timers into a
larger counter. Only the trailing edge of the TC signal can be used as input to another
Counter/Timer. For example, concatenating CTU0 and CTU1 requires the following
PPLD equation in the PSDabel file:
In order for a TC signal to come out, its respective bit in the Port E Special Function Out
Register must be set to 1. TC signals on Port E pins can be used as inputs to the ZPLD.
A TC signal goes high for the duration of at least four CLKIN periods whenever its
corresponding Timer Counting-Register overflows or underflows.
Figure 41 gives the timing relationship between CLKIN and the TC signal.
<
(External Clock input)
(DIV)
= DIV
TC - SIGNAL
CLKIN
2. Underflow occurs when a counter value changes from 0000h to FFFFh during decrementing.
mc2t mr1 = tc0;
<
= 280. Refer to Table 22 for exact values of DIV for different clock values.
30ns
*
K and N = (4 + DLCY).
4 CLKIN PERIODS
<
= DLCY
<
= 31 set up in the
30ns